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PORT WORKS

MANUAL

海港工程

手冊Design, Constructionand Maintenance

設計，建造

及維修

Civil Engineering Department土木工程署

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© Hong Kong Government © 香港政府

First published, December 1992. 一九九二年十二月初版 (英文版 )Second Edition, December 1996. 一九九六年十二月以中英文再版

Prepared by : 編寫﹕

Civil Engineering Office, 香港九龍何文田公主道1 0 1號Civil Engineering Department, 土木工程署大樓Civil Engineering Building, 土木工程署土木工程處101 Princess Margaret Road,Homantin, Kowloon,Hong Kong.

This publication is available from : 本手冊可在以下地方購買﹕

Government Publications Centre, 政府刊物銷售處Ground Floor, Low Block, 香港金鐘道6 6號Queensway Government Offices, 金鐘道政府合署低座地下66 Queensway,Hong Kong.

Overseas orders should be placed with : 海外郵購訂單請寄往﹕ Publications (Sales) Office, 香港灣仔Information Services Department, 駱克道1 8 8號28th Floor, Siu On Centre, 兆安中心2 8字樓188 Lockhart Road, Wan Chai, 政府新聞處Hong Kong. 政府刊物銷售組

Price in Hong Kong : HK$50 香港價格﹕5 0港元Price overseas : US$12 (including surface

postage)海外價格﹕1 2美元 (包括平郵費用 )

An additional bank charge of HK$50 orUS$6.50 is required per cheque made incurrencies other than Hong Kong dollars.Cheques, bank drafts or money ordersmust be made payable to HONGKONG GOVERNMENT.

凡以外幣支票付款，每票須附加銀行費用5 0港元或6 . 5美元。支票、銀行匯票或本票，必須寫上抬頭人

為「香港政府」。

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FOREWORD

The Port Works Manual offers general guidance onthe design, construction and maintenance of marinestructures in Hong Kong. The Manual was firstpublished in English in December 1992 afterconsultations with practitioners. Since then it has beenwidely circulated as a useful reference for portengineering works in the territory.

This second edition presents the original Englishversion and its Chinese counterpart in a parallelformat. The opportunity has been taken to rectifyminor typographic errors in the first edition and toup-date the environmental data and basiccharacteristics of vessels. These data were respectivelyprovided by the Royal Observatory, MarineDepartment and local ferry operators whoseconstributions are gratefully acknowledged.

This second edition was prepared by Mr LeungKin-man, Mr Ma Pak-fai and Mr Tso Man-lun, staff ofthe Civil Engineering Office under the supervision ofMr Shiu Wing-yu. The Chinese translation work wasassisted by Mr Jiang Ju-yao and Ms Li Ling-ling of theTianjin Research Institute of Water TransportEngineering.

Practitioners are encouraged to offer comments atany time to the Civil Engineering Office on thecontents of this Manual, so that improvements can bemade to future editions.

C C ChanPrincipal Government Civil Engineer

前言

《海港工程手冊》主要是為從事設計、

建造及維修港口設施的專業人士，提供一

般技術及應用指引。英文版於一九九二年

十二月出版，之前曾進行廣泛諮詢，獲得

不少寶貴意見，所以該手冊出版後，能廣

為業內人士參考使用。

本手冊主要翻譯自該英文版本及以中

英合併形式再版。同時，亦修訂了其中有

關香港氣象及船舶的資料。這些資料由皇

家香港天文台、海事處及有關渡輪公司供

給，本處謹在此表示謝意。

本手冊的出版工作由土木工程處蕭永

如先生督導，由梁建文先生、馬 輝先生

及曹曼麟先生統籌及校對。內文翻譯處理

得到天津水運工程科學研究所的蔣雎耀

先生及李苓苓女士協助。

我們希望有關業內人士能就本手冊的

內容提供意見，以確保本處可以制訂更好

的技術指引，供業界參考。

土木工程處處長

陳展津

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CONTENTS 目錄

Page No.頁數

TITLE PAGE 標題頁 2

FOREWORD 前言 3

CONTENTS 目錄 5

1. INTRODUCTION 引言 11

1.1 Scope 範圍 111.2 Definitions and Symbols 定義和符號 11

2 OPERATIONAL CONSIDERATIONS 操作考慮 13

2.1 General 概述 132.2 Design Life 設計使用期 132.3 Ship Data 船舶數據 142.4 Approach Channels 進出港航道 142.5 Berthing Conditions 靠泊條件 162.6 Currents 水流 16

3. ENVIRONMENTAL DATA 環境資料 17

3.1 General 概述 173.2 Winds 風 17

3.2.1 Collection Stations 觀測站 173.2.2 Mean Hourly Wind Speeds 歷時一小時的平均風速 173.2.3 Mean Wind Speeds for Durations

Exceeding One Hour歷時超過一小時的平均風速 18

3.2.4 Mean Wind Speeds for Durations Lessthan One Hour

歷時不足一小時的平均風速 18

3.2.5 Maximum Gusts 最高陣風 193.2.6 Pictorial Summaries of Wind Direction

and Speed風玫瑰圖 19

3.3 Waves 波浪 193.3.1 General 概述 193.3.2 Ship Observations 船上觀測 203.3.3 Wave Recording and Analysis 波浪記錄與分析 213.3.4 Wave Prediction from Local Wind

Records用風速記錄推算波浪特性 21

3.3.5 Transformation of Offshore WaveCharacteristics

離岸波浪特性的變化 24

3.3.6 Selection of Wave Parameters 波浪參數的選擇 243.4 Tides and Water Levels 潮汐和水位 243.5 Currents 水流 263.6 Joint Probability 各種因素聯合作用的可能性 273.7 Wave Overtopping 越堤浪 27

4. LOADS 荷載 29

4.1 General 概述 294.2 Loading Conditions and Combinations 正常荷載條件 29

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Page No.頁數

4.2.1 Normal Loading Conditions 荷載條件及組合 304.2.2 Extreme Loading Conditions 極端荷載條件 314.2.3 Temporary Loading Conditions 臨時荷載條件 324.2.4 Accident Loading Conditions 意外荷載條件 33

4.3 Dead Loads 恒載 344.4 Superimposed Dead Loads 附加恒載 344.5 Live Loads 活荷載 34

4.5.1 Determination of Imposed Live Loads 活荷載的確定 344.5.2 Determination of Continuous Live

Loads持續活荷載的確定 35

4.6 Hydrostatic Loads 靜水壓力 364.7 Soil Pressures 土壓力 364.8 Temperature Variations 溫度變化 374.9 Tides and Water Level Variations 潮汐和水位變化 374.10 Winds 風荷載 394.11 Currents 水流 40

4.11.1 Steady Drag Forces 穩定水流力 414.11.2 Flow-induced Oscillations 水流引起的振動 41

4.12 Waves 波浪 414.12.1General 概述 414.12.2 Design Wave Parameters 設計波浪參數 424.12.3 Calculation of Average Maximum Wave

Height平均最大波高的計算 43

4.12.4 Depth-limited Situations 受水深限制的情況 444.12.5 Calculation of Wave Forces in General 一般波浪力的計算 454.12.6 Wave Forces for Reflective Conditions 反射情況下的波浪力 454.12.7 Wave Forces Using Morison's Equation 用 Morison 公式計算波浪力 464.12.8 Wave Uplift Pressures 波浪浮托力 49

4.13 Berthing 靠泊 494.13.1 General 概述 494.13.2 Assessment of Energy to Be Absorbed 吸收能量的估算 504.13.3 Berthing Reactions 靠泊反力 51

4.14 Mooring 繫泊 514.15 Earthquakes 地震 524.16 Movements and Vibrations 位移和振動 53

5. DESIGN OF FOUNDATIONS 地基設計 55

5.1 Introduction 概述 555.2 Site Investigations 現場勘測 565.3 Properties of the Ground 地質特性 565.4 Piled Foundations 樁柱地基 56

6. DESIGN OF SUSPENDED DECK STRUCTURES 承台結構的設計 59

6.1 Introduction 概述 596.2 Load Combinations and Factors 荷載組合與系數 596.3 Superstructure 上蓋結構 60

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6.4 Piles 樁柱 606.5 Durability 耐久性 60

6.5.1 Reinforced and Prestressed Concrete 鋼筋混凝土和預應力鋼筋混凝土 606.5.2 Steelwork 鋼結構 61

7. DESIGN OF SHEET PILED STRUCTURES 板樁結構的設計 63

7.1 General 概述 637.2 Corrosion Protection 銹蝕防護 63

8. DESIGN OF GRAVITY STRUCTURES 重力式結構的設計 65

8.1 General 概述 658.2 Concrete Blockwork Walls 混凝土方塊牆 65

8.2.1 General 概述 658.2.2 Ground Water Levels and Profiles 地下水的水位和分佈 668.2.3 Consideration of Settlement 沉降問題 66

9. DESIGN OF RUBBLE STRUCTURES 堆石結構的設計 67

9.1 General 概述 679.2 Design Wave 設計波浪 679.3 Stability 穩定性 69

9.3.1 General 概述 699.3.2 Design of Armour Units Using

Hudson's Formula用 Hudson 公式設計護面塊體 69

9.3.3 Structure Head Conditions 堤頭條件 709.3.4 Model Testing 模型試驗 719.3.5 Design of Armour Units Using

Van Der Meer's Formulae用 Van der Meer 公式設計護面塊體 71

9.4 Crest Level 堤頂高程 72

10. DESIGN OF RECLAMATIONS 填海工程的設計 75

10.1 General 概述 7510.2 Extent and Layout 範圍和佈置 7610.3 Reclamation Level 填築高程 7710.4 Reclamation Method 回填方法 78

10.4.1 General 概述 7810.4.2 Marine Deposit Removal 海相沉積土清除法 7910.4.3 Marine Deposit Displacement 海相沉積土排移法 7910.4.4 Controlled Thin Layer Fill Placement 控制薄層填放法 81

10.5 Miscellaneous 其他 8310.5.1 General 概述 8310.5.2 Piling 打樁 8310.5.3 Culvert Foundations 暗渠地基 84

11. CONSTRUCTION MATERIALS 施工材料 87

11.1 General 概述 8711.2 Armour Rock 護面塊石 8711.3 Fill 回填材料 87

11.3.1 General 概述 87

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11.3.2 Public Dump Material 公眾卸泥物料 8811.3.3 Selected Fill 經挑選的填料 9011.3.4 Crushed Rock 碎石 9111.3.5 Marine Fill 海相填料 91

11.4 Concrete 混凝土 9111.4.1 Reinforced and Prestressed Concrete in

General鋼筋混凝土和預應力鋼筋混凝土 91

11.4.2 Durability 耐久性 9211.4.3 Unreinforced Concrete 無配筋混凝土 9311.4.4 Underwater Concrete 水下混凝土 9411.4.5 Design 設計 95

11.5 Steel 鋼材 9511.5.1 Structural Steel in General 結構鋼概述 9511.5.2 Corrosion Protection 銹蝕防護 9511.5.3 Use of Stainless Steel 不銹鋼的使用 9611.5.4 General Guidance 一般指引 96

11.6 Timber 木材 9711.6.1 Types of Material 木材種類 9711.6.2 Design Stress 設計應力 9711.6.3 Loading Factors 荷載系數 98

11.7 Rubber 橡膠 10011.8 Piles 樁 100

11.8.1 General 概述 10011.8.2 Driven Concrete Piles 混凝土打入樁 10011.8.3 Tubular Steel Piles 鋼管樁 10111.8.4 Bored Piles 鑽孔灌注樁 10111.8.5 Fender Piles 護舷樁 10211.8.6 Sheet Piles 鋼板樁 102

11.9 Protective Measures 防護措施 10211.9.1 General 概述 10211.9.2 Life of Protective Coatings 防護層的使用期 10311.9.3 Important Points to Be Considered 考慮的要點 10411.9.4 Corrosion Protection of Steel Tubular

Piles鋼管樁的銹蝕防護 105

12. TYPES OF STRUCTURE 結構類型 107

12.1 General 概述 10712.2 Breakwaters 防波堤 10712.3 Seawalls 海堤 10812.4 Piers 碼頭 111

12.4.1 General 概述 11112.4.2 Public Piers 公用碼頭 11212.4.3 Ferry Piers 渡輪碼頭 113

12.5 Dolphins 船墩 11412.6 Pumphouses 泵房 114

12.6.1 General 概述 11412.6.2 Layout and Location 平面佈置和定位 11412.6.3 Structure and Design 結構和設計 11512.6.4 Ties and Waterstops 拉桿和止水塞 116

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Page No.頁數

12.6.5 Screens, Guides and Fittings 攔污柵、導框和配件 11712.7 Slipways and Ramps 船排和滑道 118

12.7.1 General 概述 11812.7.2 Location and Basic Dimensions 定位和基本尺度 11812.7.3 Slipway Design 船排設計 11812.7.4 Ramp Design 滑道設計 120

12.8 Navigation Aids 助航設備 12012.9 Outfalls and Intakes 排水口和進水口 12112.10 Miscellaneous 其他 123

13. CONSTRUCTION 建造 125

13.1 General 概述 12513.2 Dredging 挖泥 125

13.2.1 General 概述 12513.2.2 Preparation and Execution of Works 施工準備和執行 12513.2.3 Sampling of Dredged Materials 挖出物取樣 12613.2.4 Surveys for Dredging 挖泥測量 12813.2.5 Dumping of Dredged Material 傾卸挖出物 130

13.3 Breakwaters and Seawall Foundations 防波堤和海堤地基 13013.3.1 General 概述 13013.3.2 Preparation and Execution of Filling 回填的準備與實施 13013.3.3 Surveys for Fill Materials 回填測量 13213.3.4 Tolerances for Fill Materials 回填容許誤差 132

13.4 Concrete Blockwork Walls 混凝土方塊體牆 13313.4.1 Levelling Stones and Blocks 整平石與方塊 13313.4.2 Bermstones 護腳石 13313.4.3 Facing Stones and Copings 護面石和牆帽 134

13.5 Piers and Dolphins 碼頭和船墩 13413.5.1 Preparation of Works 施工準備 13413.5.2 Piling 打樁 13513.5.3 Fendering 護舷設備 13613.5.4 Works by Others 協調工作 136

13.6 Reclamations 填海工程 13713.6.1 Sequence of Reclamation 回填程序 13713.6.2 Precautions to Be Taken During

Reclamation填海時的注意事項 137

13.7 Underwater Blasting 水底爆破 13813.8 Material Inspection and Testing 材料檢查和試驗 138

13.8.1 General 概述 13813.8.2 Marine Fill 海相填料 13913.8.3 Rock Fill 石填料 13913.8.4 Rock Armour 護面塊石 14013.8.5 Timber for Fenders 護木 14013.8.6 Rubber Fenders 橡膠護舷 140

13.9 Completion of Works 工程竣工 14113.9.1 General 概述 14113.9.2 Completion Certificates 竣工証書 14113.9.3 As-constructed Drawings 工程竣工圖 141

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14. MAINTENANCE 保養 143

14.1 Maintenance Inspections 維護性檢查 14314.1.1 Routine Inspections 常規檢查 14314.1.2 Special Inspections 特別檢查 14314.1.3 Inspection Procedures 檢查程序 143

14.2 Dredging 挖泥 14414.2.1 General 概述 14414.2.2 Sampling and Surveys 取樣與測量 14414.2.3 Maintenance Dredging Adjacent to

Structures結構附近的維護性疏浚 145

14.2.4 Maintenance Dredging of Rivers andNullahs

河流與水道的維護性疏浚 145

14.3 Piers and Dolphins 碼頭和船墩 14614.3.1 Piles 樁 14614.3.2 Decks 碼頭面板 14814.3.3 Fendering Systems 護舷設備 15014.3.4 Steps and Landings 階梯和登岸平台 15214.3.5 Miscellaneous Items 雜類項目 152

14.4 Blockwork Seawalls 方塊海堤 15414.4.1 General 概述 15414.4.2 Repairs to Rubble Mounds 修補堆石基床 15514.4.3 Repairs to Concrete Blocks 修補混凝土塊體 15514.4.4 Repairs to Granite Facing 修補花崗岩面層 15614.4.5 Repairs to Concrete Coping 修補混凝土牆帽 156

14.5 Rubble Seawalls and Breakwaters 堆石海堤和防波堤 15714.6 Ramps and Slipways 滑道和船排 15814.7 Pumphouses 泵房 15914.8 Navigation Aids 助航設備 15914.9 Estimates of Future Maintenance 預算保養費用 159

14.9.1 General 概述 15914.9.2 Estimates for Dredging 預算疏浚費用 16014.9.3 Estimates for Maintenance of Piers 碼頭的預算保養費用 16014.9.4 Estimates for Maintenance of Seawalls 海堤的預算保養費用 16114.9.5 Estimates for Maintenance of

Breakwaters防波堤的預算保養費用 161

REFERENCES 參考文獻 163

TABLES 附表 169

List of Tables 附表目錄 171Tables 附表 173

FIGURES 附圖 187

List of Figures 附圖目錄 189Figures 附圖 191

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1. INTRODUCTION

1.1 Scope

This Manual offers guidance on the design,construction and maintenance of those marine worksand structures which are normally constructed by theHong Kong Government. Such works and structuresinclude breakwaters, seawalls, public piers, ferry piers,dolphins, reclamations, pumphouses, slipways, rampsand navigation aid supports. However, it should alsoprovide a source of useful data and design guidancefor other marine works in Hong Kong.

The recommendations in this Manual are forguidance only. Because of the nature of the loadsinvolved, the design of marine structures reliesparticularly on the use of sound engineering judgementand experience.

1.2 Definitions and Symbols

The definitions given in BS 6349:Part 1 (BSI,1984a), Section 1.3 apply. The Glossary of Termsgiven in the Shore Protection Manual (CERC, 1984)Volume II, Appendix A may also be useful forreference. Where symbols are not defined in the text,the standard meanings for the symbols given in BS6349:Part 1 and other quoted references, asappropriate to the context, apply.

1 . 引言

1 . 1 範圍

本手冊主要為香港政府興建的海事工

程和結構，在設計、建造和維修方面提供

指引。範圍包括防波堤、海堤、公用碼頭、

渡輪碼頭、靠船墩、填海工程、泵房、船

排、滑道及導航設施。此外，香港的其他

海事工程，亦可以將本手冊提供的數據和

設計指引作為參考。

手冊中提出的各項建議，僅作為指

引。由於海事結構承受的荷載性質複雜，

設計時一定要參照以往的經驗，再輔以準

確的專業判斷。

1 . 2 定義和符號

本手冊內詞彙的定義，以《 B S 6 3 4 9 :

P a r t 1》 ( B S I , 1 9 8 4 a ) 第 1 . 3節為根據。

《 S h o r e P r o t e c t i o n M a n u a l》 ( C E R C ,

1 9 8 4 ) 第二卷附錄Ａ列出的詞彙，也可作

為參考。手冊內使用的符號，若未有註明

定義，可根據上下文意思，採用《B S 6 3 4 9 :

P a r t 1》和有關參考文獻的標準含意。

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2. OPERATIONAL CONSIDERATIONS

2.1 General

This Chapter gives guidance on general aspectssuch as the design life of structures, ship data,approach channels and other operationalconsiderations. Appropriate advice should beobtained from the Director of Marine, Commissionerfor Transport, other concerned GovernmentDepartments as appropriate, and the ferry operators,on all operational matters.

2.2 Design Life

The design life of a structure is taken to be itsintended useful life, and will depend on the purposefor which it is required. The choice of design life is amatter to be decided in relation to each project.Unless special circumstances apply, the design life forall permanent marine structures covered by thisManual should be taken to be 50 years.

Design life and return period are not the same andshould not be confused. If the return period for anevent is numerically equal to the design life, then thereis about a 63% chance of the event occurring withinthe design life. Recommended return periods arecovered in other sections.

The design life is significant when assessing :

(a) time dependent factors affecting the stability ofthe structure, such as fatigue loading, corrosion,marine growth and soil strength reductions,

(b) probability levels for limit state design and fordesign condition return periods, and

(c) economic feasibility of the project and futuredevelopments.

2 . 操作考慮

2 . 1 概述

本章對海事結構的設計使用期、船舶

數據、進出港航道等操作考慮提供指引。

有關操作上的問題應向海事處、運輸署及

其他有關的政府部門和渡輪公司查詢。

2 . 2 設計使用期

海事結構的設計使用期，是指按其用

途而定的預期有效使用壽命。選擇設計使

用期時，須考慮每項工程本身的特點。除

特殊情況外，本手冊所涉及的永久性海事

結構設計使用期都應定為 5 0年。

設計使用期和重現期有不同定義，不

應混淆。如果某一事件的重現期與結構的

設計使用期相同，那麼這一事件在該設計

使用期內發生的概率約為 6 3 %。有關重現

期的設定，將在其他章節中闡述。

在研究下列課題時，設計使用期是其

中要素：

( a ) 隨時間而變化且會影響結構穩定性

的因素，如疲勞荷載、銹蝕、海洋

附殖物和土壤強度衰減等，

( b ) 極限狀態設計和設計條件重現期的

概率，及

(c) 未來發展及工程項目在經濟方面的

可行性。

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2.3 Ship Data

Where possible, details and dimensions should beobtained from the Director of Marine, the client,owners and operators of the vessels to beaccommodated, and those likely in the anticipatedlifetime of the structure. Vessel characteristics whichshould be considered include type, size and shape, shiphandling requirements, cargo or passenger handlingrequirements, and vessel servicing requirements.

Basic characteristics of local vessels taken from theLocal Craft Registry provided by the Director ofMarine are given in Table 1. Basic characteristics of theferries owned by three of the major ferry operators atthe time of going to press are given in Tables 2 to 4.All values should be checked with the Director ofMarine or the ferry operators as appropriate beforebeing used for design purposes. Information on othervessels using Hong Kong as a port of call should besought from the appropriate authorities whenrequired.

2.4 Approach Channels

The depth and width of approach channels shouldbe specified or approved by the Director of Marine.The required depth can be calculated taking intoaccount the following factors :

(a) the design vessel loaded draft,

(b) the tide,

(c) vessel squat,

(d) vessel pitching and rolling,

(e) vessel trim, and

(f) an empirical factor giving an under-keelclearance to facilitate manoeuvrability,economic propeller efficiency and a factor ofsafety.

2 . 3 船舶數據

有關船舶細節和尺寸的數據應盡可能

從海事處、有關營運部門、可能停靠船舶

的船公司等處搜集。應考慮的船舶數據包

括其類型、尺寸和形狀、船舶操作、貨物

裝卸和乘客上落船設備與船舶檢修的要

求。

由海事處本地船隻登記處提供的本地

船舶基本數據，載列於表 1。三間主要渡

輪公司在本手冊付印時擁有的渡輪基本

數據，載列於表2至表 4。把這些資料用於

設計時，應與海事處或渡輪公司核對，確

定其是否依然適用。至於以香港作為中轉

港的船舶資料，可向有關的管理機構查

詢。

2 . 4 進出港航道

進出港航道的深度和寬度由海事處規

定或批准。所需深度可根據下述因素計

算﹕

( a ) 設計船舶的滿載吃水，

( b ) 潮汐，

(c) 船舶航行時的附加吃水，

( d ) 船舶的縱搖和橫搖，

( e ) 船舶縱傾度，及

( f ) 與船舶可操縱性、推進器效率和安

全系數有關的龍骨下富裕深度。

15

The required channel width depends upon thefollowing factors :

(a) the beam, speed and manoeuvrability of thedesign vessel,

(b) whether the vessel is to pass another vessel,

(c) the channel depth,

(d) the channel alignment,

(e) the stability of the channel banks, and

(f) the winds, waves, currents and crosscurrents inthe channel.

The above factors are covered in detail by Bruun(1981), the National Ports Council (1981) and theDepartment of Transport (1982a, b & c).

Where the bottom of the channel consists of mudit is usual in international ports to define the depth fornavigation as being that between low water level andthe level at which the density of the bottom sediment isequal to or greater than 1200 kg/m3, since researchelsewhere has shown that mud layers of lower densitydo not significantly impede the passage of a ship. Itshould be noted that, depending on its operatingfrequency, an echo sounder will identify muds ofsignificantly lower density at the seabed, whereas asounding lead will sink until supported by muds ofgreater density than 1200 kg/m3. This aspect iscovered in more detail in other chapters, but it shouldbe noted that such measurement of density requiresspecialist equipment which may not be readilyavailable.

When planning the location of approach channels,and approaches or fairways in general, account shouldbe taken of future siltation and maintenance.Dredging should be carried out to a depth greaterthan the minimum required navigation depth, with theintention of eliminating the need for maintenancedredging for at least two and preferably five yearsafter completion of initial dredging.

所需的航道寬度取決於下述因素﹕

( a ) 設計船舶的最大寬度、速度和可操

縱性，

( b ) 是否需要在航道內超越另一船隻，

(c) 航道的深度，

( d ) 航道定線，

( e ) 航道邊坡的穩定性，及

( f ) 風、波浪、航道內的水流和橫向環

流。

以上資料可從 Bruun (1981), National

Ports Council (1981), Department of

Transport (1982a、b 及 c ) 等處獲得。

如果航道的海底屬於泥質時，國際海

港通常會把通航深度定為從低水位到航

道底部淤泥密度等於 1 2 0 0 k g / m 3泥面的

距離，因為研究發現低於該密度的淤泥

層，對航行阻礙不大。應該留意的是，聲

納測深儀能按其使用的頻率，測定密度很

低的泥層，而測深錘卻只可測得密度高於

1 2 0 0 k g / m 3的泥層。這方面將在其他章

節論述。量度淤泥密度需要專門的儀器，

但這些儀器不容易得到。

規劃包括引航道和主航道的進出港航

道時，須顧及未來的泥沙淤積和保養問

題。為了在基建挖泥後，能至少在兩年，

甚至五年內不需要維護疏浚，在初次挖泥

時的深度，應低於設計的最小航行深度。

16

2.5 Berthing Conditions

Acceptable wave conditions at berths for ferriesand public vessels or within cargo handling basins andtyphoon shelters can only be determined afterconsultation with the Director of Marine, and ferryand other vessel operators. Guidance on acceptablewave conditions for moored vessels is given in BS6349:Part 1 (BSI, 1984a), Sections 30 and 31, andsome suggestions on port operation criteria have beenmade by Binnie & Partners (1987).

2.6 Currents

Major sea defence, reclamation or dredging workmay cause changes in the pattern of tidal flow andconsequently affect navigation, mooring and berthingforces, siltation and water quality in the vicinity of thereclamation or dredging site, and possibly somedistance from the site. During planning of the project,advice should be sought from the Civil EngineeringDepartment and Environmental ProtectionDepartment on whether detailed mathematical orphysical modelling studies will be necessary.

2 . 5 靠泊條件

在確定渡輪和公共碼頭、貨物裝卸作

業水域以及避風塘內的容許波浪條件之

前，應先諮詢海事處、渡輪公司及其他船

舶公司。《B S 6 3 4 9 : P a r t 1》 ( B S I , 1 9 8 4 a )

第 3 0節和 3 1節，載有關於繫泊船隻的容

許波浪條件指引； B i n n i e & P a r t n e r s

( 1 9 8 7 ) 亦提出了有關港口作業標準的建

議。

2 . 6 水流

大規模的海岸堤防 、填海和挖泥工

程，都可能引起潮流特性的變化，從而對

填海或挖泥區域，甚至附近一定範圍內的

通航、繫泊和靠泊力、泥沙淤積和水質產

生影響。在規劃工程項目時，應聽取土木

工程署和環境保護署的意見，以便確定是

否有必要進行詳細的數學及物理模型試

驗。

17

3. ENVIRONMENTAL DATA

3.1 General

This Chapter gives information related to theenvironmental records available for Hong Kongconditions with regard to winds, waves, currents andsea levels, and gives guidance on the assessment ofextreme values.

Five day means of meteorological elements forHong Kong from 1961 to 1990 are given in Table 5.These have been taken from Surface Observations inHong Kong 1990 (RO, 1990).

3.2 Winds

3.2.1 Collection Stations

The locations of the stations at which theObservatory has made wind observations for 10years or more are shown in Figure 1. For details ofthese stations, covering such aspects as date of firstobservation, type of anemometer and height abovemean sea level, reference may be made to Chin &Leong (1978).

3.2.2 Mean Hourly Wind Speeds

Mean hourly wind speeds in metres/second forreturn periods of 5, 10, 20, 50, 100 and 200 years forfour of the main stations, the Observatory, Kai TakAirport (SE), Waglan Island and Cheung Chau aregiven in Tables 6 to 9. The assessment was carriedout by the Observatory by applying Gumbel'smethod to the annual maximum mean hourly windspeeds for the eight directions for each of the stations.The period of records used for each station is given inTables 6 to 9. The figures in Table 6 should be usedwith care because of the effects of urbanisation onwinds after 1959; reference may be made to Chin &Leong (1978) for details of this effect.

3 . 環境資料

3 . 1 概述

本章列出香港有關風、浪、水流和水

位等環境資料的記錄。同時，還為估算各

種環境參數的極端值提供指引。

表 5列出香港從一九六一年到一九九

零年有關氣象要素的五天平均值，它們取

自 《 S u r f a c e O b s e r v a t i o n s i n H o n g

K o n g 1 9 9 0》 ( R O , 1 9 9 0 )。

3 . 2 風

3 . 2 . 1 觀測站

由天文台操作，有超過十年風速觀測

紀錄的觀測站位置，示於圖 1。關於這些

觀測站的詳細情況，如首次觀測日期、風

速儀的型號和高度等 ，可參閱 C h i n &

L e o n g ( 1 9 7 8 )。

3 . 2 . 2 歷時一小時的平均風速

表 6至表 9列出在四個主要觀測站重現

期為 5、1 0、2 0、5 0、1 0 0和 2 0 0年的一小

時平均風速，單位為m / s。這四個觀測站

位於天文台、啟德機場（東南）、橫瀾島

和長洲。這些數據，是香港天文台採用每

站在八個方位錄得的每年最高一小時平

均風速，經G u m b e l法分析而得出的結

果。各站所用記錄的年期，也在表6至表 9

中列出。因為一九五九年以後風速受到都

巿化效應影響，使用表 6的數據時應特別

小 心 ， 詳 情 可 參 考 C h i n & L e o n g

( 1 9 7 8 )。

18

The mean hourly wind speeds given in Tables 6 to9 may be considered for design purposes to havebeen corrected to the standard height of 10 m abovemean sea level. No corrections have been applied tothe speeds recorded at the Observatory for thereasons stated by Chin & Leong, although therecording height varies from 47 to 72 m above meansea level, or to the Kai Tak Airport (SE) speeds, witha recording height of 10 to 16 m above mean sealevel. Although the Observatory station has thelongest series of wind observations, the data are by nomeans homogenous due to the building developmentand changes in the instrumentation and height of theanemometer over the years. Hence, the windinformation for the Observatory station should beused with due care and discretion. Minor correctionsto the Waglan Island and Cheung Chau speeds, whichhave recording heights of 75 and 92 m above meansea level respectively, have been made in line with theguidelines given by Chin & Leong, following advicefrom the Observatory. It should be noted that thenormal wind-height adjustment formulae, includingthe power law referred to by the Shore ProtectionManual (SPM) (CERC,1984), are not recommendedby the Observatory for use in Hong Kong conditions.

3.2.3 Mean Wind Speeds for Durations Exceeding One Hour

Mean wind speeds for durations of 2, 3, 4, 6 and10 hours and return periods of 5, 10, 20, 50, 100 and200 years for Waglan Island NE, E, SE, S and SWdirections and for Cheung Chau SE, S and SWdirections are given in Tables 10 to 17. Theassessment was carried out by the Observatory,applying Gumbel's method to the annual means foreach duration and direction. Again, the wind speedsgiven can be considered for design purposes to havebeen corrected to the standard height of 10 metresabove mean sea level.

3.2.4 Mean Wind Speeds for Durations Less than One Hour

For conversion of the mean hourly wind speeds

如果在設計時使用表6至表 9的數據，

可以假設它們已經過換算，相等於在平均

海平面上 1 0米標準高度的一小時平均風

速。實際上，儘管在天文台的觀測站，測

量高度在平均海平面上 4 7到 7 2米之間不

等，它的風速記錄並未予以修訂，其原因

如C h i n & L e o n g 所述。同樣地，啟德機

場（東南）的測量高度也在平均海平面上

1 0到 1 6米，那裏的記錄亦未有修訂。雖

然在天文台的觀測站有最長期的風速觀

測資料，但由於期間附近的建築物發展，

測量設備的變化和風速儀測量高度的不

同等原因，減低了這些數據的可靠性。因

此，使用該站的風速資料時應十分慎重。

根據天文台的建議，在橫瀾島和長洲的風

速資料已依據 C h i n & L e o n g 的指引稍作

修正。這兩個觀測站的測量高度，分別是

平均海平面上 7 5和 9 2米。應該留意的是，

天文台認為一些常用的風速高度換算公

式，包括《 S h o r e P r o t e c t i o n M a n u a l》 (下

稱《 S P M》 ) ( C E R C , 1 9 8 4 ) 提到的指數

定律，均不適宜在香港的情況下使用。

3 . 2 . 3 歷時超過一小時的平均風速

表 1 0至表 1 7列出橫瀾島的東北、 正

東、東南、正南及西南方向和長洲東南、

正南及西南方向，重現期分別為 5、 1 0、

2 0、5 0、1 0 0及 2 0 0年及歷時為 2、3、4、

6及 1 0小時的平均風速。這些數據是由天

文台經G u m b e l法分析各種歷時和方位

的年均值而推算出的。同樣，列出的數據

在設計時可以假設為已換算到在平均海

平面上 1 0米標準高度的風速。

3 . 2 . 4 歷時不足一小時的平均風速

設計時若要從一小時平均風速換算到

19

to mean speeds corresponding to durations of lessthan one hour, the following conversion factors arerecommended for design purposes :

Duration Conversion Factor

1 minute 1.19 5 minutes 1.1120 minutes 1.05 1 hour 1.00

3.2.5 Maximum Gusts

For information on maximum gusts, referencemay be made to Chen (1975) and Poon (1982).Additional useful information concerning thefrequency and duration of tropical cyclone warningsignals for the period from 1946 to 1990 is given bythe RO (1991).

3.2.6 Pictorial Summaries of Wind Direction and Speed

Pictorial summaries of the frequency distributionof wind direction and speed measurements, in theform of wind roses, are given for the four stationsreferred to in Section 3.2.2 on an annual basis inFigure 2.

3.3 Waves

3.3.1 General

General notes on wave characteristics andproperties are given in BS 6349:Part 1 (BSI, 1984a),Sections 21.1, 21.2 and 21.3, and the SPM, pages 2-3to 2-11. Estimates of extreme wave conditions at asite should ideally be obtained by extrapolating aseries of wave measurements made at or close to thesite. However, because of the relatively high cost ofsetting up a wave recording system, and the need forrecords covering a suitable period (not less than oneyear) to enable sufficiently reliable extrapolation, nodirect wave record will be available for the vast

歷時不足一小時的平均風速，建議使用以

下的換算系數﹕

歷時 換算系數

1分鐘 1 . 1 9

5分鐘 1 . 1 1

2 0分鐘 1 . 0 5

1小時 1 . 0 0

3 . 2 . 5 最高陣風

關於最高陣風的資料，可參閱 C h e n

( 1 9 7 5 ) 和 P o o n ( 1 9 8 2 )。另外，天文台

( R O , 1 9 9 1 ) 出版了一九四六年至一九九

零年關於熱帶氣旋警報信號的頻率和歷

時等資料。

3 . 2 . 6 風玫瑰圖

圖 2是利用在第 3 . 2 . 2節提到的四個觀

測站所錄得的風速資料而繪製的風玫瑰

圖，這些風玫瑰圖顯示以整年計的風向頻

率和風速強弱。

3 . 3 波浪

3 . 3 . 1 概述

波浪性質和特性的一般說明可參考

《 B S 6 3 4 9 : P a r t 1》 ( B S I , 1 9 8 4 a ) 第

2 1 . 1、 2 1 . 2及 2 1 . 3節和《 S P M》 第 2 - 3

頁至 2 - 1 1頁。要推算一特定地點的極端

波況，最理想的方法是利用該處或其附近

的現場實測波浪數據。但是，因為設立波

浪觀測記錄系統費用頗高，並且需要頗長

的觀測時間（不少於一年），才能得到可

靠的數據，故此本手冊所涉及的絕大多數

海事結構，都沒有可直接利用的波浪記

錄。

20

majority of marine structures covered by this Manual.

In Hong Kong waters, the most severe waveconditions are usually associated with storm wavesand, in the absence of wave records, wave forecastingfrom wind records can be used to predict suchconditions, as outlined in later sections. In somesituations, particularly where there is direct exposureto the South China Sea and longer period waves aretherefore considered important, swell waves fromdistant storms should be taken into account duringdesign. If no direct wave records are available,information on swell waves can be obtained fromexisting wave records elsewhere or from visual waveobservations made by ships' crews.

Because of the complex geographical features inHong Kong waters, waves propagating into suchwaters are likely to be transformed by processes suchas refraction, diffraction, reflection and seabedfriction. These processes may have significantinfluence on the wave climate in the area to bestudied. The designer has to assess these factors at anearly stage to ascertain whether more sophisticatedanalysis has to be carried out. Computer models areavailable for such analysis and are recommended foruse in studying the wave transformation in complexareas. These models have to be calibrated to makesure that they are suitable for that particular study area.

3.3.2 Ship Observations

It is generally accepted that predictions based on alarge number of observations from ships made bydifferent people can give a useful estimate of waveconditions. Records of ship observations within thearea of the South China Sea bounded by longitudes100°E and 120°E and by latitudes 0°N and 25°Nare kept by the Observatory. Reference may be madeto Lam (1979, 1980), although it should be noted thatthe areas covered by these studies include somerelatively protected inshore regions. If informationon swell waves is required from ship observations fora particular project, an open area of sea should beconsidered when approaching the Observatory for

在香港水域，最惡劣的波浪通常和風

暴有關。在缺乏波浪觀測記錄的情況下，

可利用風速記錄來推算海浪的情況，這些

將在以下的章節論述。在某些情況下，特

別是在面向南海的地區，設計時的考慮，

應包括從遠處暴風區傳來有較長周期的

湧浪。若無直接的波浪記錄可用，湧浪資

料可參考其他地區已有的波浪記錄，或利

用船上觀測所得的資料。

由於香港水域地理條件複雜，傳入的

波浪極可能透過折射、繞射、反射和海底

摩擦等現象，產生變化。這些變化可能會

對研究區域的波況產生很大影響。設計人

員必須事先評估這些因素，以確定是否需

要進行更詳細的分析。部分數學模型具有

這種分析功能，因此可用來研究複雜地區

的波浪變化。這些模型須先經驗證，以確

定是否適用於該特定的研究區域。

3 . 3 . 2 船上觀測

由船舶上人員觀測所得的大量海浪實

測資料，經過分析後可得出有實用價值的

波浪數據，此種辦法早已被採用。天文台

存有南海水域從東經 1 0 0 o到 1 2 0 o，北緯0 o

到 2 5 o 範圍內的船測記錄。這方面的資料

可參考L a m ( 1 9 7 9 , 1 9 8 0 )，但應指出的

是，這些研究所涉及的區域包括了一些受

掩蔽的近岸地區。如果需要就具體的工程

項目，向天文台索取船上測得的湧浪資料

時，應選擇開敞海域範圍的資料。南海的

波 浪 數 據 也 可 從 H o g b e n , D a c u n h a &

O l l i v e r ( 1 9 8 6 ) 中獲得。

21

details of records held. Wave data for the SouthChina Sea can also be obtained from Hogben,Dacunha & Olliver (1986).

Offshore wave climate has been derived fromship observation records given in Binnie & Partners(1989). Data were taken from the sea area 18.8°N to21.9°N and 112.0°E to 115.0°E, comprising some24,000 observations from 1949 to 1985. The datawere divided into 30° directional sectors centredupon 60°, 90°, 120°, 150°, 180°, 210°, 240° and270°. The eight resulting distributions of significantwave height have been extrapolated to extremes usingthe Weibull fitting.

3.3.3 Wave Recording and Analysis

For general information on wave recording andanalysis, reference may be made to BS 6349:Part 1,Section 26. Wave records at Waglan Island have beenkept by the Observatory since 1971. For details,reference may be made to Apps & Chen (1973),Chen (1979a, 1979b) and Cheng (1986).

It should be noted from the latest of the abovepublications that there were several recording systembreakdowns when waves reached heights of nine toten metres and that no return period/wave heightanalysis was carried out due to the limited number ofrecords available for analysis. The returnperiod/wave height information given by Chen(1979b) should not be used without checking with theObservatory concerning the latest wave records.Details of wave height observations made at WaglanIsland between 1959 and 1966 are given by Cuming(1967).

3.3.4 Wave Prediction from Local Wind Records

For wave prediction from local wind records, it isrecommended that the charts given in the SPMshould be used : Figure 3-23 should be used fordeep-water waves and Figures 3-27 to 3-36 for

B i n n i e & P a r t n e r s ( 1 9 8 9 ) 列出由船上

觀測記錄推算到的離岸區波況。這些數據

是從東經 1 1 2 . 0 o 到 1 1 5 . 0 o 和北緯 1 8 . 8 o 到

2 1 . 9 o 的海域範圍內測得的，其中包括一

九四九年至一九八五年的約2 4 , 0 0 0個觀

測值。這些數據按方位劃分，每 3 0 o一個

扇區，並分別以6 0 o、9 0 o、1 2 0 o、1 5 0 o、

1 8 0 o、 2 1 0 o、 2 4 0 o 和 2 7 0 o 為中心，共分

成八個扇區。在這八個方位 ，已應用

W e i b u l l及外推法推算了極端的有效波高

值。

3 . 3 . 3 波浪記錄和分析

關於波浪記錄和分析的一般資料，可

參閱《B S 6 3 4 9 : P a r t 1》第 2 6節。天文台

保存自一九七一年到今天，在橫瀾島取得

的波浪記錄，有關詳情可參閱 A p p s &

C h e n ( 1 9 7 3 )，C h e n ( 1 9 7 9 a及 1 9 7 9 b ) 和

C h e n g ( 1 9 8 6 )。

但根據C h e n g ( 1 9 8 6 ) 的描述，部分的

記錄在波高達到 9至 1 0米時便中斷了，同

時由於適用的數據不足，而無法進行重現

期和波高分析。在採納C h e n ( 1 9 7 9 b ) 記

載的重現期／波高分析資料前，應向天文

台查證最新的波浪記錄。C u m i n g ( 1 9 6 7 )

載有一九五九年至一九六六年間，在橫瀾

島取得的波高觀測資料。

3 . 3 . 4 用風速記錄推算波浪特性

如果要用風速記錄推算波浪情況，建

議使用《 S P M》 中的圖表：圖 3 - 2 3用於

深水波，圖 3 - 2 7至 3 - 3 6用於淺水波。

本手冊的圖 3至圖 7，是以《 S P M》 中的

22

shallow-water waves. Figures 3 to 7 of this Manualare based on Figures 3-23, 3-30, 3-32, 3-34 and 3-36of the SPM, but with the range of wind stress factorextended up to 100 m/s to allow for local conditions.When using these figures, the significant wave periodcan be taken as 0.95 times the peak spectral period fordesign purposes, see the SPM, page 3-47.

The estimation of fetch length for the directionbeing considered should be based on the methodgiven in Section V, page 3-42 of the SPM, whichconsiders a 24° sector centred on that direction, andinvolves the arithmetic averaging of a number ofequally spaced radials within that sector. Beforeconverting any wind speed from Tables 6 to 9 orTables 10 to 17 to a wind stress factor by applyingequation 3-28a of the SPM, the application ofcorrection factors for stability and location inaccordance with page 3-30 of the SPM is required.For the prediction of waves generated by tropicalstorms, a stability correction factor of 1.1 may beused for air/sea temperature adjustment. A locationcorrection factor of 1 is recommended, as allanemometer stations considered are relatively close toshore.

For 'fetch-limited' situations, mean hourly windspeeds from Tables 6 to 9 may be used for initialwave prediction, after correction for stability andlocation but, for final wave prediction, the correctedmean hourly wind speed should be adjusted using theconversion factor appropriate for the actual criticalduration, as read from the wave prediction curves.Conversion factors for durations of less than onehour are given in Section 3.2. Linear interpolationbetween the figures given will be sufficiently accuratefor other durations. As an example, for a correctedmean hourly wind speed of 48 m/s and a fetch of 2km, the corresponding wind stress factor of 83.0 m/sgives a deep-water significant wave height of 1.9 mand a peak spectral period of 3.4s (significant waveperiod 3.2s) from Figure 3, with a critical duration of20 min. As this critical duration is different from onehour, the mean hourly wind speed must be adjustedfor this duration. From Section 3.2, the conversionfactor for a 20 minute duration is 1.05. For the

圖 3 - 2 3、 3 - 3 0、 3 - 3 2、 3 - 3 4和 3 - 3 6

為基礎製成的。為了符合本地的自然環

境，圖中的風壓系數已增加至 1 0 0 m / s。

應用這些圖表時，有效波周期可取譜峰周

期的 0 . 9 5倍，詳情可參閱《 S P M》 第 3 -

4 7頁。

至於風區長度，可以利用《 S P M》 第

3 . 4 2頁第V 節提供的方法推算，這個方法以所要考慮的方向為中心，設定一個 2 4 o

的扇區，把扇區分成相等的若干部分，然

後求出每個部分徑向長度的算術平均

值。在應用《 S P M》公式 3 - 2 8 a將表 6至

表 9或表 1 0至表 1 7的風速轉換為風壓系

數前，須先用《 S P M》第 3 - 3 0頁列出的

穩定和方位修正系數進行換算。在推算由

熱帶風暴產生的波浪時，穩定修正系數可

取 1 . 1，用以調整空氣和海水的溫度。由

於所有的風速觀測站都靠近海岸，因此建

議方位修正系數為 1。

在「有限風區」的情況下，表 6至表 9

的一小時平均風速，經過穩定和方位修正

之後，可用來進行初步波浪推算，但是在

最後的波浪推算，修正過的平均風速還應

用適當的歷時換算系數來校正，該系數應

與從波浪推算曲線上查出的實際的臨界

歷時相符合。歷時不超過一小時的歷時換

算系數，已在第3 . 2節列出。對於表中未

列出的其他歷時，可利用已列出的資料進

行線性內插法求得。舉一例說明，設修正

後的歷時一小時平均風速為 4 8 m / s，風

區長度為 2公里，相應的風壓系數為 8 3 . 0

m / s，由圖 3可查得其深水波有效波高為

1 . 9米，譜峰周期為 3 . 4秒（有效波周期為

3 . 2秒），其臨界歷時為 2 0分鐘。由於該

臨界歷時不是一個小時，因此必須對該歷

時的平均風速加以校正 。從第 3 . 2節 可

知，歷時為2 0分鐘時，換算系數為1 . 0 5。

校正後的平均風速為 5 0 . 4 m / s，風區長

度不變，仍為 2公里，相應的風壓系數變

23

corrected mean 20 minute wind speed of 50.4 m/sand the same fetch of 2 km, the corresponding windstress factor of 88.2 m/s gives a deep-watersignificant wave height of 2.0 m and a peak spectralperiod of 3.5s (significant wave period 3.3s). Fordurations greater than one hour, the conversion factorfor the adjustment of the mean hourly wind speedcan be assessed from Tables 10 to 17.

For fetch-limited situations, several directionsshould be considered, as the most severe waveconditions will not necessarily correspond with thedirection which has the longest fetch. Mean hourlywind speeds for directions other than those given inTables 6 to 9 should be interpolated by anappropriate method.

For situations which are not fetch-limited, a seriesof durations and corresponding mean wind speeds,taken from Tables 10 to 17, should be considered foreach direction, before the most critical waveconditions can be determined. The mean windspeed/duration distributions given in Tables 10 to 17differ for different locations and directions. Whenusing Figure 3 for wave prediction from the windspeed/duration figures for some directions, it will befound that there is a maximum off-shore significantwave height corresponding to a particular durationless than about ten hours, and within the range of twoto six hours. However, for other directions, it will befound that the wave height continues to increase as theduration increases from 2 to 25 hours, and there is noapparent maximum. For durations greater thanabout 10 hours, particular care should be taken whenassessing wave heights. It is recommended that theObservatory is consulted in such circumstances, andother methods of wave prediction and assessmentshould be used. The use of Figure 3 for waveprediction is based on the assumption that windsmeasured in Hong Kong waters apply equally withregard to strength, duration and direction over therespective fetch being considered. This assumption isreasonable for relatively short durations of severalhours, which correspond to fetches of less than about100 km for 100 year return period winds. However,for durations exceeding ten hours, which correspond

為 8 8 . 2 m / s，由其引起的深水波有效波

高為 2 . 0米，譜峰周期為 3 . 5秒（有效波周

期為 3 . 3秒）。當歷時大於一小時的時候，

用來校正平均風速的換算系數，可從表1 0

至表 1 7查得。

在有限風區的條件下，應考慮多個不

同方向的狀況，因為最惡劣的海浪情況不

一定是在風區最長的方向。部分方向的平

均風速，並未包括在表6至表 9內，可用適

當的內插法估算。

在無限風區的情況下，在確定每個方

向的最嚴峻波況以前，應該考慮表1 0至表

1 7列出的不同歷時及相應的平均風速的

效應。表 1 0至表 1 7列出的平均風速／歷

時分佈，隨不同的位置和方向而改變。如

果參照圖 3進行海浪推算，便可以發覺某

些方向的風速／歷時數值，在歷時小於十

小時的情況下（一般在二至六小時的範圍

內），會出現最大離岸有效波高。然而在

其他方向，則可發現當歷時由二小時增加

到 2 5小時的時候，波高會隨之加大，而沒

有明顯的最大值。因此，當歷時大於十小

時的時候，估算波高應特別慎重，應向天

文台查詢，同時亦應採用其他方法進行海

浪預測和估算。運用圖 3推算海浪時，是

假設了該風區範圍內的風強度、歷時和方

向，都和港海內的觀測結果相同。如果歷

時較短，只有數小時的時間，這項假設是

合理的；例如風重現期為 1 0 0年的話，其

相應風區長度會不超過 1 0 0公里。然而，

如果歷時超過十小時，而風重現期同樣為

1 0 0年的話 ，風區長度便會超過 2 0 0 公

里，再加上這些極端風通常都與熱帶風暴

有關，上述的假設未必能成立。

24

to fetches greater than about 200 km for 100 yearreturn period winds, there is increasing doubt aboutthis assumption, particularly as such extreme windswill be associated generally with tropical stormconditions.

3.3.5 Transformation of Offshore Wave Characteristics

For the transformation of offshore wavecharacteristics into inshore wave characteristics,covering such aspects as refraction, shoaling anddiffraction, reference should be made to BS6349:Part 1, Sections 23.2 and 29 and the SPM, pages2-60 to 2-108. Breaking waves are covered by BS6349:Part 1, Section 23.4, and the SPM, pages 2-129to 2-136. Further useful comments on breaking andnonbreaking waves and design wave conditions aregiven in the SPM, pages 7-1 to 7-16. Wheninvestigating whether a structure will be subjected tobreaking or nonbreaking waves, all possible sea levelsshould be considered. For some structures inrelatively shallow water, breaking waves at low sealevels will be critical, whereas nonbreaking waveconditions will apply at higher sea levels.

3.3.6 Selection of Wave Parameters

Guidance on the selection of design waveparameters for particular types of structure is given inother sections. Wave height parameters in terms ofsignificant wave height are given in the SPM, page 7-2. Notes on the average maximum wave height andits relationship with the significant wave height, andthe number of waves in the duration of the designcondition, are given in BS 6349:Part 1, Section 27.3.2,and also in Section 4.12 of this Manual.

3.4 Tides and Water Levels

The locations of tide gauges under the control ofthe Observatory at the time of going to press aregiven in Figure 8. Tide Tables are published each yearby the Observatory. These give predicted times and

3 . 3 . 5 離岸波浪特性的變化

研究離岸波浪轉變成近岸波浪（包括

折射、變淺和繞射等），可參考《B S 6 3 4 9 :

Par t 1》第 2 3 . 2節和 2 9節以及《 S P M》第

2 - 6 0頁至 2 - 1 0 8頁。《B S 6 3 4 9 : P a r t 1》

第 2 3 . 4節和《 S P M》第 2 - 1 2 9頁至 2 - 1 3 6

頁，都有論及破碎波。有關破碎波、非破

碎波及設計波浪條件的進一步論述，可見

於《 S P M》第 7 - 1頁至 7 - 1 6頁。研究結

構是受破碎波還是非破碎波影響時，應該

考慮整個的水位變化幅度。對於一些位於

淺水區域的結構來說，低水位時破碎波可

能是最嚴峻的，而非破碎波會在水位較高

時出現。

3 . 3 . 6 波浪參數的選擇

本手冊其他章節，提供了為特定類型

海事結構選擇的設計波浪參數的指引。

《 S P M》 第 7 - 2頁列出了與有效波高有

關的波高參數。關於平均最大波高及其與

有效波高的關係，以及在設計歷時內出現

的波數，在《B S 6 3 4 9 : P a r t 1》第 2 7 . 3 . 2

節和本手冊第 4 . 1 2節中都有說明。

3 . 4 潮汐和水位

圖 8顯示現時由天文台負責操作的潮

位計位置。天文台每年均印製潮汐表，表

中列出每個觀測站的預測高潮位和低潮

位的時間和高程。潮位高程為海圖基準面

25

heights of high and low waters at the tide stations.Tide levels are given in terms of Chart Datum (CD),which is 0.146 m below Principal Datum (PD).

Useful information on storm surges in HongKong during the period from 1906 to 1982, and theassessment of extreme sea levels for the tide gaugelocations at North Point (since replaced by QuarryBay in 1986), Tai Po Kau and Chi Ma Wan forvarious return periods, is given by Chan (1983).

Updated extreme sea level analyses have beencarried out by the Observatory for QuarryBay/North Point, Tai Po Kau, Ko Lau Wan, TsimBei Tsui and Waglan Island. Extreme sea levels forreturn periods of 2, 5, 10, 20, 50, 100 and 200 yearsfor these five locations are given in Tables 18 to 22.The period of records used in each case is given in theTables. At each location, the assessment was carriedout by fitting a Gumbel distribution to the annualmaximum sea levels and using the method ofmoments in parameter estimation.

Lowest still levels observed at the tide stationsshown in Figure 8 are as follows :

Station Sea Level (mCD)

North Point -0.16Quarry Bay -0.12Chi Ma Wan -0.13Ko Lau Wan -0.13Lok On Pai -0.28Tai O -0.52Tamar -0.17Tsim Bei Tsui -0.21Tai Po Kau -0.26Waglan Island -0.17

Probable minimum sea levels at North Point havebeen estimated by the Observatory using Gumbel'smethod, and are as follows :

( C D ) 以上高度，該基準面比水平基準面

( P D ) 低 0 . 1 4 6米。

C h a n ( 1 9 8 3 ) 提供了一些關於一九○

六年至一九八二年期間香港風暴潮增水

的實測資料，同時也列出了位於北角（自

一九八六年起被 魚涌站取代）、大埔滘

和芝麻灣的潮位計所在水域，在不同重現

期下極端水位的估計值。

天文台更新了 魚涌／北角、大埔

滘、高流灣、尖鼻咀和橫瀾島的極端水位

分析。表 1 8至表 2 2列出在這五個地點，

重現期分別為 2、 5、1 0、2 0、5 0、1 0 0和

2 0 0年的極端水位，分析使用的記錄年期

也在表中列出。計算的程序是先應用

G u m b e l法找出每年最高水位的分佈曲

線，然後利用力矩法估算出有關參數。

在圖 8顯示的潮汐觀測站所測到的最

低靜水位為﹕

觀測站 海水位 ( m C D )

北角 - 0 . 1 6

魚涌 - 0 . 1 2

芝麻灣 - 0 . 1 3

高流灣 - 0 . 1 3

樂安排 - 0 . 2 8

大 澳 - 0 . 5 2

舊添馬艦海軍基地 - 0 . 1 7

尖鼻咀 - 0 . 2 1

大埔滘 - 0 . 2 6

橫瀾島 - 0 . 1 7

北角站的最低水位 ，由天文台利用

G u m b e l法估算出來，如下所列﹕

26

Return Period (years) Sea Level (mCD)

2 05 -0.1010 -0.1520 -0.2050 -0.30100 -0.35200 -0.40

3.5 Currents

Indications of current speeds for Hong Kongwaters are given in the Admiralty Tidal Stream Atlas,Hong Kong (Taunton, 1975). Additionalinformation on currents in specific locations can beobtained from reports prepared by consultants forvarious Government departments over the last fewyears. The Civil Engineering Department, TerritoryDevelopment Department, EnvironmentalProtection Department and Marine Departmentshould be consulted in the first instance for details ofstudies carried out in any areas for which informationon currents is required.

It is possible to predict representative currentswithin Hong Kong waters using the WAHMO suiteof models held by Government. The computer-based mathematical models cover the whole of HongKong waters and include simulation of the two-layereffect in the wet season due to the Pearl River flow.In addition, the physical tidal model may be used forpredictions inside Victoria Harbour for the dryseason.

For locations where no information on existingcurrents is available, it may be necessary to carry outmeasurements on site.

General notes on current meter observations andfloat tracking are given in Sections 11.2.2 and 11.2.3of BS 6349: Part 1. The period of measurementshould depend on flow characteristics in the area ofinterest and aspects of the study for which the currentdata is needed. It should also be set in such a way asto give an indication of velocity distribution with

重現期（年） 海水位 ( m C D )

2 0

5 - 0 . 1 0

1 0 - 0 . 1 5

2 0 - 0 . 2 0

5 0 - 0 . 3 0

1 0 0 - 0 . 3 5

2 0 0 - 0 . 4 0

3 . 5 水流

《 A d m i r a l t y T i d a l S t r e a m A t l a s ,

H o n g K o n g》 ( T a u n t o n , 1 9 7 5 ) 說明了

香港水域的水流速度。從近年各政府部門

顧問完成的研究報告中，也可找到部分水

域的水流資料。在對任何水域進行深入研

究，而需要水流資料時，應先諮詢土木工

程署、拓展署、環境保護署和海事處。

政府的水力及水質模型 ( W A H M O

M o d e l s )，可以用來預測香港水域的典型

水流情況。其中的數學模型，覆蓋了全港

水域，同時也模擬了雨季時因珠江徑流引

起的分層現象。此外，實體潮汐模型也可

用來預測維多利亞港旱季時的情況。

在沒有現成水流資料的水域，可能需

要進行現場測量。

《B S 6 3 4 9 : P a r t 1》第 1 1 . 2 . 2節和 1 1 . 2 . 3

節，載有利用流速儀觀測和浮標追蹤觀測

的一般說明。測量期長短，取決於研究區

域內的水流特性，以及水流數據將用於何

種研究。由於某些地區在雨季的分層現象

比較明顯，因此應該量度不同水深的流速

分佈和流向。

27

depth below water level, and of direction as in someareas, stratification may be significant in the wetseason.

3.6 Joint Probability

Some of the worst conditions that should beconsidered in relation to the design of coastal defenceworks are those which involve the combination ofextreme sea level with severe wave action. Thiscombination does not necessarily mean adding thepredicted extreme still water level directly to theseparately estimated extreme wave height value.There is a need to determine the degree of correlationbetween these two variables so that an appropriatechoice can be made in relation to each type ofstructure in the light of the purpose for which it isbeing designed.

The astronomical tide is considered anindependent factor while the meteorological factorsof storm surge and wave attack are linked. Thedegree of correlation can vary between different sites.Joint probability analysis is therefore recommendedto establish such correlation, especially for largeprojects for which the cost implications can be verysignificant.

3.7 Wave Overtopping

Assessment of the amount of overtopping isneeded to determine the crest level. As guidance, thepermissible volumes of overtopping water can befound in Fukuda, Uno & Irie (1974) and Goda(1971). However, the designer should examine eachindividual case to decide whether more conservativefigures or otherwise, have to be adopted. The factorsto be considered should include consequences ofexcessive overtopping, drainage behind the seawalland reliability of design parameters.

The amount of overtopping can be estimated byvarious methods. Two of the most commonly usedones are detailed in Goda (1971) and HydraulicsResearch Station (1980). These methods have been

3 . 6 各種因素聯合作用的可能性

設計海岸防護工程時，應考慮最不利

的情況。當考慮極端水位與惡劣的波浪條

件同時出現時，並不一定代表須將推算到

的極端靜水位與分別估算出的極端波高

直接相加，而是須要確定這兩種變量之間

的相互關係，以便因應各類海事結構的不

同用途，作出適當的選擇。

在這裏，天文潮應當視為一個獨立的

因素，但與氣象有關的風暴潮增水和海浪

擊則是有相互關連的，其相關程度會因

地點不同而變化。因此，應對各種因素一

同出現的概率加以分析，以確定其相互關

係。對於造價較高的大型工程來說，是項

研究更為重要。

3 . 7 越堤浪

確定海事結構的頂高程時，須考慮越

堤浪的數量。F u k u d a , U n o & I r i e ( 1 9 7 4 )

和G o d a ( 1 9 7 1 ) 載有越堤浪的容許量。然

而，設計人員還應對個別情況加以分析，

以確定應否採用更為保守的數值。考慮的

因素應包括大量越堤浪造成的後果、海堤

旁的排水情況及設計參數的可靠程度。

目前有多種方法可以估算越堤浪的數

量；G o d a ( 1 9 7 1 ) 和H y d r a u l i c s R e s e a r c h

S t a t i o n ( 1 9 8 0 ) 詳述了最常用的兩種方

法。它們都是以不規則波模型試驗的結果

28

based on results of model tests using irregular waves.It is recommended that model tests should be carriedout as far as is possible to verify the predicted amountof overtopping.

為基礎的。建議盡可能進行模型試驗，以

便核實有關越堤浪的估算。

29

4. LOADS

4.1 General

This Chapter describes the loading conditionswhich should be considered in the design of marinestructures (excluding rubble structures, which arecovered in Chapter 9) and includes information on theloads to be taken into account. Guidance is given onthe selection of relevant design parameters andmethods of calculation to derive the resulting directforces on structures, taking into account the nature andcharacteristics of the structures.

In addition to dead loads, superimposed deadloads, hydrostatic loads and soil pressures, the otherforces which may act on marine structures areenvironmental, arising from such natural phenomena aswinds, temperature variations, tides, currents, wavesand earthquakes, and those imposed loads due tooperational activities. General imposed loads coverlive loads from pedestrians, vehicles, cargo storage andhandling. Vessel imposed loads cover berthing,mooring and slipping.

Unless stated otherwise, the design loads given inthis Chapter are unfactored and can be used directlywhere appropriate in checking geotechnical instabilitymodes, in design of piled foundations, see Section 5.4,and of steel structures using the working stress methodof design, see Section 6.3. Guidance on appropriatepartial factors for limit state design is to be found inother sections.

4.2 Loading Conditions and Combinations

The structure as a whole, or any part or section,should be designed and checked for at least the loadingconditions given below. If it is expected that otherloading conditions could be critical, they should also beinvestigated. Various types of load should becombined in a manner consistent with the probabilityof their simultaneous occurrence.

4 . 荷載

4 . 1 概述

本章闡述海事結構 （不包括堆石結

構，該種結構將在第九章論述）設計過程

中須考慮的荷載條件，和荷載的資料。本

章還對計算在結構上的作用力時，怎樣因

應結構本身特性，而選擇適當的設計參數

和計算方法，提供指引。

除恒載、附加恒載、水壓力和土壓力

以外，還有一些荷載可能會施加在結構

上，它們可以是由風、溫度變化、潮汐、

水流、波浪和地震等自然現象引起的環境

荷載，或是由操作活動而引起的使用荷

載。一般使用荷載包括由行人、車輛、貨

物的貯存和裝卸產生的活荷載。而船舶荷

載包括由於船舶靠泊、繫泊和走錨而產生

的荷載。

除另有說明外，本章闡述的設計荷載

都是未加系數的。在進行樁柱地基設計

時，這些荷載可以被直接用來檢驗地基的

不穩定模式（見本手冊第 5 . 4節）。同時，

在採用許用應力法設計鋼結構時，也可直

接使用（見本手冊第 6 . 3節）。關於使用

極限狀態設計法時的分項系數，本手冊在

其他章節提供了指引。

4 . 2 荷載條件及組合

無論對結構的整體或局部進行設計和

檢核，最低限度應包括以下的幾種荷載條

件。如認為其他荷載條件也有嚴重影響

時，則也應一併考慮。不同種類的荷載，

應根據它們同時出現的概率組合起來。

30

4.2.1 Normal Loading Conditions

These loading conditions are those in which normaloperations continue unaffected by environmentalconditions. A combination of the following should beconsidered :

(a) dead loads,

(b) superimposed dead loads,

(c) live loads due to normal working operations(the most severe arrangement likely to occursimultaneously),

(d) vessel imposed loads (berthing and mooring),

(e) normal environmental loads (winds, currentsand waves),

(f) soil pressures, and

(g) hydrostatic loads.

Guidance on the calculation of environmental loadsassociated with normal working operations is givenlater in this Chapter under each type of loadingcondition. It should be assumed that maximumimposed live loads can occur simultaneously withmaximum vessel imposed loads from either berthingor mooring, whichever gives the most severe effect,unless the size or geometry of the structure indicatesthat it is possible for certain mooring loads to occur atthe same time as berthing. In this latter case, the mostsevere combination of berthing and mooring loadsshould be determined by the designer and thiscombination assumed to occur simultaneously withmaximum imposed live loads.

For normal environmental loads, it should beassumed that maximum loads from winds, currentsand waves can occur simultaneously. All directionsshould be considered when assessing the most severeeffects from these loads.

When combining the effects of maximum imposedloads due to normal working operations with

4 . 2 . 1 正常荷載條件

這是指在不受自然環境影響正常作業

情況下的荷載條件。其組合應包括以下荷

載﹕

( a ) 恒載，

( b ) 附加恒載，

(c) 正常作業產生的活荷載（可能出現

的最嚴苛組合），

( d ) 船舶荷載（靠泊和繫泊時的荷載），

( e ) 正常環境荷載（風、水流和波浪），

( f ) 土壓力，及

( g ) 靜水壓力。

本章稍後會論述在各種荷載條件下，

計算在正常作業時的環境荷載的方法。在

正常情況下，應假設最大使用活荷載可與

由靠泊或繫泊引起的最大船舶荷載同時

出現，並取其影響較大者。在某些情況

下，結構的外形和尺寸顯示部分繫泊力會

與靠泊力同時出現，此時應由設計人員確

定靠泊荷載和繫泊荷載的最嚴苛組合，並

假設這一組合與最大使用活荷載同時出

現。

考慮正常環境荷載時，應假設分別由

風、水流和海浪產生的最大荷載，有可能

同時出現。在估算這些荷載給結構造成的

最嚴重影響時，應包括所有可能的方向組

合。

組合正常作業下的最大使用荷載與最

大正常環境荷載時，應考慮到靠泊或繫泊

31

maximum normal environmental loads, the possibleshielding effect caused by a vessel when berthing ormooring should be considered. For certain structures,e.g. dolphins, it may not be realistic to assume that fullberthing or mooring loads can occur simultaneouslywith full wind, current and wave loads.

4.2.2 Extreme Loading Conditions

These loading conditions are associated with themost severe environmental conditions which thestructure is designed to withstand. It is assumed thatunder these conditions most normal operations, suchas vessel berthing and mooring, pedestrian and vehiclemovements, and cargo storage and handling, will haveceased. A combination of the following should beconsidered :

(a) dead loads (same values as for Normal LoadingConditions),

(b) superimposed dead loads (these may bedifferent from Normal Loading Conditions),

(c) reduced live loads (if any at all) due to continuingoperations,

(d) reduced vessel-imposed loads (if any) due tocontinuing operations,

(e) extreme environmental loads (winds, currents,waves and temperature variations),

(f) soil pressures (same values as for NormalLoading Conditions), and

(g) hydrostatic loads (in some cases, these will bedifferent from Normal Loading Conditions).

It should be assumed for extreme environmentalloads that maximum effects from winds, currents andwaves can occur simultaneously, but maximum effectsfrom temperature variations should be consideredseparately. Vessel-imposed loads can be ignored under

中的船舶可能對結構產生的遮擋效應。對

一些結構來說，如靠船墩，假設最大船舶

荷載與最大環境荷載同時出現是不合理

的。

4 . 2 . 2 極端荷載條件

這種荷載條件與結構設計所能承受的

最惡劣自然環境有關。在這種荷載條件

下，大多數正常的作業活動，如船舶靠泊

和繫泊、行人和車輛活動，以及貨物貯存

和裝卸等都會停止。此時應考慮下列荷載

組合﹕

( a ) 恒載（與正常荷載條件相同），

( b ) 附加恒載（可能與正常荷載條件不

同），

(c) 因繼續作業而尚存的活荷載（若有

的話），

( d ) 因繼續作業而尚存的船舶荷載（若

有的話），

( e ) 極端環境荷載（風、水流、波浪和

氣溫變化），

( f ) 土壓力（與正常荷載條件相同），

及

( g ) 靜水壓力（在某些情況下可能與正

常荷載條件不同）。

極端環境荷載，應假設由風、水流和

波浪產生的最不利作用可以同時出現，而

由溫度變化產生的最不利作用則應獨立

考慮。在由風、水流和波浪造成的極端環

境情況下，不應再有船舶荷載，因為這種

32

extreme environmental conditions from winds,currents and waves, as these will occur during tropicalcyclone conditions when normal vessel movementswill have ceased. However, vessel-imposed loadsshould be combined with maximum effects fromtemperature variations. Guidance on live loads to beconsidered under extreme environmental conditionsfrom winds, currents and waves is given in Section 4.5.Normal maximum live loads should be combinedwith maximum effects from temperature variations, asthese variations will not occur during tropical cycloneconditions.

Unless stated otherwise, the extreme environmentalconditions for structures having a design life of 50 yearsshould be taken as those having return periods of 100years. This is a conservative assumption intended totake account of the occurrence of tropical cyclones andthe relatively short periods for which most records areavailable. Where special circumstances apply, resultingin a shorter or longer design life, the return periodshould be adjusted accordingly. It should be noted thatfor an event with a return period of 100 years, there isapproximately a 1% chance of occurrence in any oneyear and approximately an 18%, 40% and 63% chanceof occurrence in a 20 year, 50 year and 100 year periodrespectively. Reference can be made to Section 21.4 ofBS 6349:Part 1 (BSI, 1984a) for the method ofcalculation. In any event, under Hong Kongconditions, where at present the periods ofenvironmental records are relatively short, resulting insome degree of lack of confidence in assessedextremes, the true chance of occurrence may well beunderestimated by using the formula.

4.2.3 Temporary Loading Conditions

Temporary Loading Conditions are those whicharise during construction, towing, installation or thecarrying out of unusual but foreseeable operations,such as the application of a test load. For theseconditions, a combination of the appropriate dead andmaximum temporary loads, together with theassociated environmental loads, should be considered.

情況必定在熱帶風暴吹襲時出現，在這樣

惡劣的天氣下，一般船舶活動都會停止。

不過，由溫度變化造成的極端條件，則應

該與船舶荷載組合。在由風、水流和波浪

造成的極端環境情況下應考慮的活荷

載，可參考本手冊第 4 . 5節的指引。最大

正常活荷載，應該與溫度變化造成的最不

利影響組合，因為這種溫度變化與熱帶風

暴沒有關係。

除另有說明外，否則設計使用期為 5 0

年的結構，其極端環境情況的重現期應為

1 0 0年。這是一個保守的假設，但卻顧及

了熱帶風暴吹襲的可能性和多方面的記

錄均相對地不足。若情況特殊，採用了不

同的設計使用期，則重現期也應作相應的

調整。值得留意的是，一個重現期為 1 0 0

年的環境情況，它在任何一年裏發生的概

率均為 1﹪，而在2 0年、 5 0年和 1 0 0年的

期限內發生的概率，則分別約為1 8﹪、4 0

﹪和 6 3﹪。計算方法可參考《 B S 6 3 4 9 :

P a r t 1》 ( B S I , 1 9 8 4 a ) 第 2 1 . 4節。香港現

有水文氣象的記錄時間均較短，以致估算

得的極端值可靠性並不理想，因此，利用

上述公式計算出來的實際發生概率很可

能偏低。

4 . 2 . 3 臨時荷載條件

這是指那些在施工、拖帶、安裝設備

的過程中，或在一些不經常出現但可預見

的操作過程中產生的荷載條件，如進行試

驗時的荷載條件。在這種情況下，應該考

慮恒載、最大臨時荷載，以及相應的環境

荷載的組合情況。臨時設計荷載和環境荷

載，都取決於結構所在的位置以及施工或

33

Temporary design and environmental conditionsshould be appropriate for the location, and for thetime of year, when the construction or operation willbe carried out.

4.2.4 Accident Loading Conditions

Accident Loading Conditions are those whichoccur during accidental impact by a vessel. For theseconditions, a combination of dead, superimposeddead and hydrostatic loads, soil pressures, live loadsand normal environmental loads, together with theappropriate accident berthing load, should beconsidered. Guidance on accident berthing loads isgiven later in this Chapter. The above combination isto some extent artificial, as an accident can occur at atime of normal or extreme environmental loadingconditions. However, it is not normally necessary tocombine accident berthing loads with maximumimposed loads and extreme environmental loadsbecause of the low probability of their simultaneousoccurrence. It is not necessary for all marine structuresto be designed or checked for accident loadingconditions. The need for checking will depend on :

(a) the importance of the structure,

(b) the location with respect to normal ferry routesand fairways,

(c) the degree of exposure to adverseenvironmental conditions,

(d) the expected degree of use if the structure is apier, and

(e) the susceptibility to damage of the type ofdesign used.

Public and ferry piers, except those expected tohave a particularly low level of use and in a particularlyprotected location, should generally be designed orchecked for accident loading conditions. For suchaccident loading conditions, damage to minorstructural members which can be readily repaired, and

運作的時間。

4 . 2 . 4 意外荷載條件

這是指船舶意外撞擊海事結構時，產

生的荷載條件。在這種情況下，應考慮恒

載、附加恒載、靜水壓力、土壓力、活荷

載、正常環境荷載，以及適當的船舶意外

靠泊力的組合。本章稍後會提供計算意外

靠泊力的指引。上述荷載的組合，只是人

為設定，因為無論是在正常或在極端環境

荷載條件下，都有可能發生意外。然而，

由於意外靠泊力，最大使用荷載和極端環

境荷載同時出現的機會很小，因此一般情

況下不必採用這個組合。並非所有的海事

結構都須設計或檢核在意外荷載條件下

的情況，這取決於﹕

( a ) 結構的重要性，

( b ) 與渡輪航線和主航道的相對位置，

(c) 結構暴露在不利環境條件下的程

度，

( d ) 結構的使用頻率（對碼頭而言），

及

( e ) 採用的設計類型，是否容易受到損

壞。

公用和渡輪碼頭的設計與檢核，通常

應包括其在意外荷載條件下的情況，只有

當其預計使用率偏低，且處於特別安全的

位置時，才可以作例外處理。如在意外荷

載條件下的損壞，只局限於容易修復的次

要結構部分，和諸如護舷之類的構件，設

34

to such items as fenders, can be accepted at thediscretion of the designer.

4.3 Dead Loads

The dead load is the weight of the structuralelements of the structure, including any substructure,piling and superstructure. The weight of the structure isits weight in air. Where parts are wholly, partially orintermittently immersed in water, upthrust on thoseparts should be calculated separately, as recommendedin Section 4.6.

4.4 Superimposed Dead Loads

The superimposed dead load is the weight of allmaterials imposing loads on the structure that are notstructural elements, and should include surfacing, fixedequipment, fenders, bollards, handrails, ladders,walkways, stairways, services, fittings and furniture.For all loading conditions, the possibility of any of thesuperimposed dead loads being removed should beconsidered.

4.5 Live Loads

The imposed live loads include all loads which thestructure has to withstand except dead, superimposeddead, hydrostatic, soil, vessel-imposed andenvironmental loads and, in the case of concretestructures, loads from such effects as prestress andcreep, which are treated separately in other sections.Where appropriate, the imposed live loads should betaken as equal to those defined in, and calculated inaccordance with, BS 6399:Part 1 (BSI, 1984b).

4.5.1 Determination of Imposed Live Loads

The determination of imposed live loads due tonormal working operations for various structuresshould be in accordance with the following.

(1) Public Piers. The live load for the main decks of

計人員可酌情接納。

4 . 3 恒載

恒載是指海事結構構件的重量，包括

所有地基結構、樁柱和上蓋結構。結構的

重量是指其在空氣中的重量，如果結構的

構件全部、部分或間中浸在水中，在這些

構件上的浮力荷載應獨立計算，如本手冊

第 4 . 6節所述。

4 . 4 附加恒載

附加恒載並不源自結構本身，而是附

加在結構上的所有物料的重量，包括面

層、固定設備、護舷設備、繫船柱、欄桿、

爬梯、行人道、樓梯、管線設施、配件以

及機械等。在考慮各種荷載條件，都要顧

及部分附加恒載被移走的可能性。

4 . 5 活荷載

活荷載包括了除恒載、附加恒載、靜

水壓力、土壓力、船舶荷載和環境荷載以

外，結構所要承受的所有荷載。至於混凝

土結構，更應減去由預應力和徐變等現象

產生的荷載，它們將在其他章節中分別論

述。在一般情況下，活荷載應按《B S 6 3 9 9 :

P a r t 1》 ( B S I , 1 9 8 4 b ) 的規定取值，並

按其提供的方法計算。

4 . 5 . 1 活荷載的確定

各類海事結構在正常作業時承受的活

荷載應按下列指引確定﹕

( 1 )公用碼頭﹕在公用碼頭主要面板上

35

public piers, to include for the movement ofpedestrians, hand luggage, ship provisions andtemporary stacking, should be taken as 10 kPa. Whereaccess to the pier by vehicles is not physically prevented,the live load should also allow for possible emergencyvehicular access by an ambulance, police vehicleand/or fire engine as appropriate and agreed with therelevant authority. The live load for any upper deckshould be taken as 5 kPa, and 2.5 kPa for a roof withno general access.

(2) Ferry Piers. The live loads for pedestrian ferry piersshould be no less than those given above for publicpiers, but should in addition be checked and agreedwith the prospective ferry operators. The live loads forvehicular ferry pier waiting areas and ramps willdepend on the types of vehicles allowed or expected touse the services, and should be agreed with theprospective ferry operators.

(3) Other Piers. The live loads for other piers should bedetermined after consultation with the prospectiveusers, taking into account the proposed use, possiblecargo storage, cargo handling equipment and vehicularaccess.

(4) Seawalls. Where no specific use has been designatedfor the area of land to be formed immediately behind aseawall at the time of design, the live load for such landfor the design of the seawall should be taken as 10 kPa.Where a specific use has been designated, the live loadshould be determined taking such use into account, butthis load should not be less than 10 kPa.

4.5.2 Determination of Continuous Live Loads

Guidance on the determination of the live load dueto continuing operations under extreme environmentalconditions from winds, currents and waves, and of thelive loads to be used in accident loading conditionsreferred to in Section 4.2, is given below.

(1) Live Loads under Extreme Environmental Conditions. Thelive loads due to continuing operations under extremeenvironmental conditions from winds, currents and

的活荷載，包括行人、手提行李、船舶供

應物資和貨物臨時堆存，應取1 0 k P a。對

於沒有圍欄阻擋車輛進入的碼頭，活荷載

還應適當地包括由救護車、警車和滅火車

等在碼頭上緊急停泊的作用力，有關數值

要得到有關機構的確認。每塊上層面板上

的活荷載都應取 5 k P a，至於沒有裝置常

設通道的頂層活荷載應取 2 . 5 k P a。

( 2 )渡輪碼頭﹕客運渡輪碼頭的活荷

載，不應小於上述用在公用碼頭的數值，

而且應得到碼頭營運者的確認。汽車渡輪

碼頭的候船停車場和引橋上的活荷載，應

根據使用碼頭的車輛種類而定，並應徵得

碼頭營運者的確認。

( 3 )其他碼頭﹕其他類型碼頭上的活荷

載，應包括碼頭將來使用時可能貯存的貨

物、貨物裝卸設備以及車輛進入時產生的

荷載，有關數值須與碼頭未來營運者商討

後確定。

( 4 )海堤﹕如果在設計時，海堤旁的土

地用途尚未明確，活荷載應取 1 0 k P a，如

果已訂明具體用途，則可以此為根據確定

活荷載的數值，但仍不應小於 1 0 k P a。

4 . 5 . 2 持續活荷載的確定

持續活荷載分為兩種﹕一種是在風、

水流和波浪形成的極端環境條件下仍繼

續作業時的活荷載；另一種是在意外荷載

條件（見第 4 . 2節）下的活荷載。

( 1 )極端環境條件下的活荷載﹕對碼頭

而言，在風、水流和波浪形成的極端環境

條件下，仍繼續作業的活荷載，通常可以

36

waves may be taken as zero for piers unless there is aspecific need or requirement for the pier to be usedduring tropical cyclone conditions, e.g. for emergenciesor storage. For seawalls, the maximum live loads onthe adjacent land due to continuing operations underextreme environmental conditions should be taken as50% of the live loads due to normal workingoperations under normal environmental conditions,unless it can be ensured with reasonable certainty thatthe land behind the seawall will not be used for thestorage or temporary stacking of materials. In thislatter case, the live load can be taken as zero. For otherstructures, the live loads due to continuing operationsunder extreme environmental conditions should beassessed by the designer. Normal maximum live loadsshould be considered to apply under extremeenvironmental conditions relating to temperaturevariations.

(2) Live Loads under Accident Conditions. The live loads tobe used in Accident Loading Conditions for normalstructures can be taken as 50% of the live loads due tonormal working operations under normalenvironmental conditions. At the discretion of thedesigner, this percentage may be reduced to 25% forstructures expected to be loaded infrequently, orincreased to 75% for structures expected to haveparticularly heavy usage such as ferry piers on majorroutes with exceptionally frequent services.

4.6 Hydrostatic Loads

When considering the effects of buoyancy, it ispreferable to represent the buoyancy and gravitationalloads as separately applied loading systems. In thisway, the effect of changes in water level can be seenmore clearly, and it is possible in limit state design toapply different load factors to dead loads andhydrostatic loads as appropriate.

4.7 Soil Pressures

Guidance on the calculation of soil pressures isgiven in BS 6349:Part 1, Section 6. Reference can alsobe made to Geoguide 1 (GEO, 1993).

刪除。在特殊情況下，如遇上緊急事故或

貯存貨物，碼頭在熱帶氣旋影響時仍須繼

續作業，則屬例外。對海堤而言，堤旁的

土地在極端環境條件下繼續作業的最大

活荷載，應取在正常環境條件下正常作業

的活荷載之 5 0﹪。但若可以肯定海堤旁的

土地不會用於貯存或臨時堆放物料，則活

荷載可以刪除。至於其他類型的海事結

構，在極端環境條件下作業的活荷載應由

設計人員估算。若極端環境條件是因溫度

變化而造成，則應採用正常情況下的最大

活荷載值。

( 2 )意外條件下的活荷載﹕對一般海事

結構來說，意外荷載條件下的活荷載，可

以取正常環境條件下，正常作業活荷載的

5 0﹪。至於一些不經常加載的結構，可考

慮把百分比降至 2 5﹪；而那些使用率特別

高的結構，例如位於重要航線上而特別繁

忙的的渡輪碼頭，則可把百分比提升至7 5

﹪。

4 . 6 靜水壓力

考慮浮力的作用時，最好是把浮力荷

載和重力荷載分別以兩個獨立的荷載系

統代表。用這種方法，可以更清楚地看到

水位變化產生的影響，而且在應用極限狀

態設計法時，恒載和靜水壓力也可分別採

用不同的荷載系數。

4 . 7 土壓力

《B S 6 3 4 9 : P a r t 1》第 6節載有計算土

壓力的指引，也可參考《G e o g u i d e 1》

( G E O , 1 9 9 3 )。

37

For the purposes of calculating soil pressures :

(a) extreme water levels should be derived asdescribed in Section 4.9,

(b) ground pore water pressures should bedetermined with reference to tidal range, soilpermeability, drainage provisions, and anyartesian and sub-artesian ground waterconditions, and

(c) allowance should be made for reduced passiveresistance due to overdredging or scour.

4.8 Temperature Variations

The loads or load effects arising from thermalexpansion or contraction of the structure and fromtemperature gradients in the structure will usually beminor in relation to other loads for marine structureswith a maximum length between joints of 50 metres,and need not be considered.

The loads arising from thermal expansion orcontraction of the structure for marine structures with alength between joints exceeding 50 metres should beassessed. This is particularly important for piers andsimilar suspended deck structures where thermalmovements of the deck induce loads in the supportingpiles. Where no specific information is availableconcerning the temperatures of the structure at the timeof construction, and the extremes expected during thedesign life of the structure, for design purposes aneffective maximum temperature drop of 25°C and aneffective maximum temperature rise of 20°C can beassumed for concrete deck structures under extremeenvironmental conditions. Under normal loadingconditions, the effects of temperature variations maybe ignored.

4.9 Tides and Water Level Variations

Information on tides and the extreme range of stillwater levels is given in Section 3.4. Such information is

在計算土壓力時﹕

( a ) 應按第 4 . 9節描述的方法推算極端

水位，

( b ) 地下孔隙水壓力應根據潮差、土壤

的透水性、排水設施及所有的承

壓、半承壓地下水情況而定，及

(c) 應考慮挖泥時，超挖和水流 刷可

能會減少被動土壓力。

4 . 8 溫度變化

海事結構的冷縮熱脹以及結構內部的

溫度梯度，都會產生荷載或荷載效應。若

結構的接縫間距小於 5 0米，則產生的荷載

和荷載效應與其他荷載相比是很小的，可

以不予考慮。

倘若結構的接縫間距超過 5 0米，則須

估算由冷縮熱脹引起的荷載。這對碼頭和

類似的承台結構尤為重要，因為這些結構

的面板遇熱變形，會增加承托樁柱上的荷

載。關於建造結構時的溫度，及其在設計

使用期內可能經受的極端溫度，如果沒有

具體的資料，則可以假設混凝土樑板結

構，在極端環境條件下，可能有2 5℃的最

大有效溫降，及 2 0℃的最大有效溫升。在

正常荷載條件下，溫度變化的影響可略而

不計。

4 . 9 潮汐和水位變化

本手冊第 3 . 4節載有潮汐和靜水位最

大變化幅度的資料。這些資料可用來計

38

required for the evaluation of :

(a) overtopping,

(b) hydrostatic pressures, including buoyancyeffects,

(c) soil pressures, and

(d) levels of action of mooring, berthing and waveforces.

In addition, the effect of waves and wave run-upshould be considered in relation to overtopping andhydrostatic pressures.

For structures with a design life of 50 years, for theloading conditions referred to in Section 4.2,maximum still water levels due to tide and surge effectscorresponding to the following return periods can beassumed :

Loading Conditions Return Period

Normal 2 yearsExtreme 100 yearsAccident 2 years

For structures where a different design life applies,the return period for extreme loading conditionsshould be adjusted accordingly.

The observed lowest levels given in Section 3.4 canbe used for Normal and Accident LoadingConditions. For Extreme Loading Conditions, thelowest water level can be assumed to be 0.3 m belowthe levels given in Section 3.4. For information on tidelevels at locations not covered by the tide stations, theObservatory should be consulted.

The range of still water level to be considered forTemporary Loading Conditions should be assessed bythe designer for each individual case.

Structures should be designed to withstand safelythe effects of the extreme range of still water level

算﹕

( a ) 越堤浪，

( b ) 靜水壓力，包括浮力效應，

(c) 土壓力，及

( d ) 船舶靠泊、繫泊和波浪等作用力的

高程。

另外 ，在確定波浪越頂和靜水壓力

時，還應考慮波浪和波浪上衝的作用。

設計使用期為 5 0年的海事結構，在第

4 . 2節論述的荷載條件下，計算因潮汐和

風暴潮增水作用形成的最高水位時，可採

用以下重現期﹕

荷載條件 重現期

正常 2年

極端 1 0 0年

意外 2年

若結構採用了不同的設計使用期時，

其極端荷載條件的重現期也應作相應調

整。

本 手 冊 第 3 . 4 節 列 出 的 最 低 觀 測 水

位，可用於正常和意外荷載條件下。在極

端荷載條件下，可假設其最低水位比第

3 . 4節列出的水位低 0 . 3米。關於潮汐觀測

站覆蓋範圍以外地區的潮位資料，可向天

文台查詢。

臨時荷載條件下靜水位的變化幅度，

可由設計人員按個別情況進行估算。

結構的設計應能安全地承受在各種荷

載條件下，上述極端靜水位所產生的影

39

referred to above for each loading condition. It shouldbe noted that for different types of structure, differentloading cases, and different conditions, the critical stillwater level may be the minimum, maximum or someintermediate level; the full range must be investigatedby the designer.

4.10 Winds

For the assessment of wind loads on marinestructures, for the loading conditions referred to inSection 4.2, the following design wind pressures maybe assumed :

Loading Conditions Design Wind Pressure

Normal 1.2 kPaExtreme 3.0 kPaAccident 1.2 kPa

For Temporary Loading Conditions, the designwind pressure should be assessed by the designer foreach individual case, taking into account the followingpoints.

(a) The design wind pressure of 1.2 kPa forNormal and Accident Loading Conditionscorresponds to a gust of about 44 m/s, which isthe maximum gust expected to occur with amean hourly wind speed of 17 m/s (33 knots).This by definition is the maximum mean hourlywind speed likely to occur while TropicalCyclone Signal No. 3 is hoisted or within thefirst few hours of the hoisting of TropicalCyclone Signal No. 8. The above assumes agustiness factor (ratio between maximum gustand mean hourly wind speed) of about 2.6,which is not normally exceeded under HongKong conditions. For details of gustinessfactors, reference may be made to Chen (1975)and Poon (1982).

(b) The design wind pressure of 3.0 kPa underextreme environmental conditions correspondsto a gust of about 70 m/s (136 knots), which isthe maximum gust expected to occur with a

響。對於不同類型的結構和不同荷載條

件，最嚴峻的靜水位，可能是最高水位，

也可能是最低水位，或處於兩者之間，所

以設計人員的研究必須涵蓋整個水位變

化幅度。

4 . 1 0 風荷載

按第 4 . 2節論述的荷載條件，評估海事

結構上的風荷載時，可採用下列設計風壓

力值﹕

荷載條件 設計風壓力

正常 1 . 2 k P a

極端 3 . 0 k P a

意外 1 . 2 k P a

對於臨時荷載條件下的設計風壓力，

設計人員可以根據個別情況，考慮下列因

素而予以確定﹕

( a ) 在正常荷載和意外荷載條件下的設

計風壓力為 1 . 2 k P a，相當於速度約

為 4 4 m / s的陣風。這是當平均風速

為 1 7 m / s ( 3 3浬 ) 時，可能出現的

最高陣風。而 1 7 m / s正是三號熱帶

氣旋警告信號懸掛以後，或八號熱

帶氣旋警告信號懸掛後的最初數小

時內，預期出現的最高平均風速。

以上論述假設了在香港的環境情況

下，陣風系數（最高陣風和平均風

速之間的比率），通常不會超過

2 . 6。有關陣風系數的詳細資料可參

考C h e n ( 1 9 7 5 ) 及P o o n ( 1 9 8 2 )。

( b ) 在極端環境條件下的設計風壓力為

3 . 0 k P a，其相對的陣風速度約為7 0

m / s ( 1 3 6浬 )。這是香港水域內，

預計重現期為 5 0年的最高陣風。

40

return period of about 50 years in Hong Kongwaters.

(c) Wind forces on structures and elements ofstructures should be calculated in accordancewith Sections 4 and 5 of BDD (1983). Furtherguidance may be obtained from CP3 (BSI,1972), Chapter V, Part 2.

4.11 Currents

Where no detailed information or records areavailable at a site where a structure is to be located, thedesign current velocity for Normal, Extreme,Temporary and Accident Loading Conditions may betaken as a constant 1 m/s at a depth of 15 metresbelow the water surface. Below 15 metres waterdepth, the current may be ignored. For most locations,particularly within the harbour area, the above will beconservative, as current forces are assumed to actsimultaneously with wave and wind forces. Forlocations near channels such as Kap Shui Mun,Urmston Road, Tolo Channel, Rambler Channel andLei Yue Mun, where above average currents areencountered, the figure of 1 m/s should not be usedwithout a detailed investigation. Where measurementsare available, the designer should assess design currentvelocities for the various loading conditions.

The direction of the design current for locationswhere no information or records are available shouldbe determined by the designer. For locations close tothe shore, the direction may normally be assumed to beparallel to the shore line. For isolated locations remotefrom the shore, it should normally be assumed that thedesign current can occur in all directions.

For the assessment of current forces on piles andother parts of structures, for all loading conditionsother than for temporary conditions duringconstruction, the area normal to flow should include anallowance for marine growth. Where no otherinformation or site measurements are available, auniform effective thickness of 100 mm of marine

(c) 在結構和結構構件上的風荷載，可

以按照B D D ( 1 9 8 3 ) 第 4節和第 5節

論述的方法計算。《 C P 3》 ( B S I ,

1 9 7 2 ) 第Ⅴ章第 2部分有進一步的

指引。

4 . 1 1 水流

如果結構座落的地點，沒有可供利用

的詳細資料或記錄，在正常、極端、臨時

和意外荷載條件下，水面以下直至1 5米深

處的設計水流速度可以取恆量 1 m / s。水

深超過 1 5米處的水流，可以省略。對於大

多數地點，特別是在港口區域內，上述取

值比較保守，因為水流荷載是假設與波浪

荷載和風荷載共同起作用的。在距離汲水

門、龍鼓水道、赤門、藍巴勒海峽和鯉魚

門等水道較近的地方，會出現超過上述速

度的水流，因此未經詳細調查，水流速度

不應取 1 m / s。若有可供利用的測量資料

時，設計人員應分別評估在各種荷載條件

下的設計水流速度。

當無任何資料或記錄可供使用時，設

計水流方向應由設計人員自行確定。如果

位置距海岸較近，水流方向可假設為與海

岸線平行；如果位置距海岸較遠，則通常

應假設設計水流在任何方向都有可能出

現。

評估在結構的樁柱和其他部分之水流

力時，除施工階段外，水面下面積應包括

海洋附殖物造成的增量。若沒有其他資料

或現場測量結果可用，可假設所有位於平

均海平面以下的結構表面上，都長有有效

厚度為 1 0 0毫米的海洋附殖物。

41

growth for all surfaces below mean sea level can beassumed.

Loads imposed by currents on marine structuresmay be classified as either drag forces parallel to theflow direction, or cross-flow forces transverse to theflow direction. Current drag forces are principallysteady; the oscillatory component is only significantwhen its frequency approaches the natural frequency ofthe structure. Cross-flow forces are entirely oscillatoryfor bodies symmetrically presented to the flow.

4.11.1 Steady Drag Forces

Steady drag forces can be calculated using theformula given in Section 38.2 of BS 6349:Part 1. Forthe assessment of drag coefficients for circularcylinders, the values corresponding to moderatemarine growth should be used unless specialcircumstances apply.

4.11.2 Flow-induced Oscillations

Notes on flow induced oscillations for piles aregiven in Section 38.3 of BS 6349:Part 1. Duringconstruction, restraint should be provided to pile headsimmediately after driving to prevent the possibility ofoscillation in the cantilever mode. For completedstructures in Hong Kong conditions, in typical waterdepths and with the types of pile normally used, it is notusually necessary to check critical flow velocities.Checks should be made for structures in particularlydeep water where slender piles are being considered,and at locations where high design current velocitiesapply.

4.12 Waves

4.12.1 General

Wave loads on a structure are dynamic in nature,but when the design wave period is much higher thanthe structure's fundamental period, as will be the casefor the vast majority of structures covered by this

由水流產生在海事結構上的荷載，可

分為平行於水流方向的水流力和垂直於

水流方向的橫向力。水流力大致上是穩定

的，其振動分力只在振動頻率接近結構本

身的振動頻率時，才有顯著的影響。若結

構構件對稱地經受水流力作用的時候，便

只有振動性的橫向水流力產生。

4 . 1 1 . 1 穩定水流力

穩定水流力可以利用《B S 6 3 4 9 : P a r t

1》第 3 8 . 2節列出的公式計算。除非在特

殊的情況下，否則估算在圓柱形構件上的

水流力系數時，應假設構件已長有中量海

洋附殖物。

4 . 1 1 . 2 水流引起的振動

《B S 6 3 4 9 : P a r t 1》第 3 8 . 3節載述了水

流在樁柱引起的振動。在施工期間，應該

在打入樁柱以後立即限制樁頭移動，以避

免樁柱可能會因水流作用而產生懸臂樑

式的振動。在香港的環境情況下，完成了

的海事結構，若採納了常用的樁柱類型，

且在典型的水深情況下，通常不須檢核臨

界流速。當考慮在深水結構中，使用細長

的樁柱，又或結構位於高設計流速的地方

時，則應該檢核臨界流速。

4 . 1 2 波浪

4 . 1 2 . 1 概述

作用在海事結構上的波浪荷載，其性

質是動態的，但當設計波浪周期遠遠超過

結構固有周期時，這種動態荷載可以用它

們的靜態等效荷載來代表，本手冊內絕大

42

Manual, these loads may be adequately represented bytheir static equivalents. Dynamic responses andvibrations are covered in Section 4.16. The crest of anydesign wave should be positioned relative to a structuresuch that the wave forces have their maximum effecton the structure. It should be noted that the maximumstress in elements of the structure may occur for wavepositions, directions and periods other than thosecausing the maximum force on the structure.

4.12.2 Design Wave Parameters

Design wave parameters depend very much on thedesign life and return period, which have to be assessedfor each individual structure. Design life is the intendeduseful life of the structure taking into account, amongstother things, changes in circumstances and operationalpractices which may make the structure redundant.Return period may vary according to the consequenceof failure, availability of data and financialconsiderations.

As a guide, for extreme environmental conditionsfor a structure having a design life of 50 years, (exceptfor rubble structures which are covered in Section 9.2),the design wave for the assessment of wave loadsshould be taken as the average of the highest 1% of allwaves (H1), which is approximately equal to 1.67 timesthe significant wave height, having a return period of100 years. For structures with different design lives, thereturn period should be adjusted accordingly.

The design wave for normal and accident loadingconditions, for the assessment of wave loads, shouldbe taken as the average of the highest 1% of all wavescorresponding to a mean hourly wind speed of 17m/s, or the equivalent wind speed adjusted forduration, as appropriate for the fetch being considered.The reason for selecting this particular mean hourlywind speed is given in Section 4.10. Where, for theparticular location and direction being considered, themean hourly wind speed for a 5 year return periodfrom Tables 6 to 9 is less than 17 m/s, a reduced meanhourly wind speed equal to this figure may be used inplace of 17 m/s. For Temporary Loading Conditions,

多數的海事結構正是這樣。第 4 . 1 6節論述

有關動態反應和振動。設計波峰應該設在

波浪力對結構影響最大的位置上。但要留

意的是，波浪在結構構件內產生最大應力

時的相位、波向和周期，可能與其在整體

結構上產生最大波浪力時不同。

4 . 1 2 . 2 設計波浪參數

設計波浪參數，很大程度上取決於設

計使用期和重現期，故此，對於不同的海

事結構，這兩個設計值都會經過獨立評估

才確定。設計使用期是指設計結構時，為

它所訂定的有效使用年期，期間考慮的眾

多因素中，應包括環境的變遷和作業方式

的改變，它們可以令結構變得再無使用價

值。重現期則可因結構損毀的後果、資料

的多寡和經濟方面的考慮而不同。

評估極端環境條件下的波浪荷載時，

若海事結構的設計使用期為 5 0年，其設計

波浪應該取重現期為 1 0 0年之最大 1﹪波

浪的波高平均值 ( H 1 )，（堆石結構除外，

此種結構將在第9 . 2節論述），這約為有

效波高的 1 . 6 7倍。對於採用了不同設計使

用期的結構，重現期也應作相應的調整。

評估波浪荷載時，正常荷載和意外荷

載條件下的設計波浪，可以用一小時平均

風速為 1 7 m / s時產生的最大 1﹪波浪的

波高平均值，或者採用按歷時調整得出的

等效風速，在有關風區長度所產生的最大

1﹪波浪的波高平均值。第 4 . 1 0節已提及

選取這個特定的平均風速的原因。在表 6

至表 9，某些地點和方向的５年重現期平

均風速是低於1 7 m / s，在這情況下，可

以 採 用 這 個 較 小 的 平 均 風 速 代 替 1 7

m / s。在臨時荷載條件下，設計人員應評

估在每種情況下的波浪參數，其中應考慮

預測的一小時平均風速或其等效值的影

43

the designer should assess the design wave parametersfor each situation, taking into account the likely meanhourly wind speed or its equivalent expected to beexperienced.

Wave loading due to swells should be checked inthe design, particularly for structures exposed to theSouth China Sea. For Normal and Accident LoadingConditions, swells having a return period of five yearscan be used in the design. A return period of 100 yearsshould be used for Extreme Loading Conditions.

4.12.3 Calculation of Average Maximum Wave Height

The designer may, in some cases, choose to adoptthe average maximum wave height for extremeenvironmental conditions. Information on the methodof calculation of average maximum wave height isgiven in Section 3.3. The ratio between the averagemaximum wave height and significant wave heightdepends on the number of waves in the design event,as follows :

Number of Waves Ratio

200 1.72400 1.81600 1.871000 1.942000 2.024000 2.11

In each case, the number of waves to be consideredin the design event, and the resulting ratio between theaverage maximum wave height to be used for designand the significant wave height, must be decided by thedesigner. As a guide, the ratio should be within therange 1.8 to 2.0, which corresponds to a number ofwaves between about 400 and 2000. Normally, theaverage maximum wave height may be taken as 1.9times the significant wave height. This corresponds toabout 750 waves in the design event which, with anassumed average period of five seconds (typical for

響。

設計時也應驗算由湧浪引起的波浪荷

載，對於那些直接受南海影響的海事結

構，這尤為重要。在正常荷載和意外荷載

條件下，設計可以採用重現期為五年的湧

浪。在極端荷載條件下，重現期則應取 1 0 0

年。

4 . 1 2 . 3 平均最大波高的計算

在某些情況下，設計人員可以選用極

端環境條件下的平均最大波高。本手冊第

3 . 3節載述了計算平均最大波高的方法。

平均最大波高和有效波高的比值，取決於

設計狀況中的波數，如下所示：

波浪數目 比率

2 0 0 1 . 7 2

4 0 0 1 . 8 1

6 0 0 1 . 8 7

1 0 0 0 1 . 9 4

2 0 0 0 2 . 0 2

4 0 0 0 2 . 1 1

在每一種情況，設計時考慮的波浪數

目，以及要採用的平均最大波高與有效波

高的比值，都必須由設計人員確定。可供

參考的是，這個比值應該在1 . 8至 2 . 0的範

圍內，其相應的波數為 4 0 0至 2 0 0 0。通

常，平均最大波高可以取有效波高的 1 . 9

倍，這對應於波浪數目約為 7 5 0的設計狀

況，並假設了平均周期為 5秒（在香港一

些較受掩護的地區，這是典型的周期），

亦對應於歷時為剛剛超過一小時的設計

狀況或風暴。在設計時，平均最大波浪與

44

relatively protected locations in Hong Kong), in turncorresponds to a duration of the design event or stormof just over one hour. For design purposes, the waveperiod corresponding to the average maximum waveheight may be taken to be equal to the significant waveperiod.

It should be noted that, although the averagemaximum wave height is close to being the mostprobable value of the maximum wave height, bydefinition the actual maximum wave height is quitelikely to exceed the average maximum wave height. Asan example, using the probability formula given inSection 27.3.2 of BS 6349:Part 1, for a group of 750waves there is about a 22% probability of themaximum wave height exceeding 2.0 times thesignificant wave height and about a 10% probability ofit exceeding 2.1 times the significant wave height.

4.12.4 Depth-limited Situations

For comments on breaking and non-breakingwaves in relation to the range of water levels to beconsidered, reference should be made to Section 3.3.It should be noted that, for some structures, the designwave will be 'depth-limited' and the design waveparameters will not correspond to those referred toabove for the various loading conditions. For thesesituations, particular care should be taken with thedesign, as the structure will be subject to breakingwaves and will be more likely to have to withstandmany waves similar in magnitude to the design waveduring its design life. For depth-limited designs, thedesign wave height will be dependent on the waterdepth at the structure, but the full range of possibleperiods should be investigated before determining thedesign wave period. As an upper bound, underdepth-limited conditions, the design wave period maybe taken to be the period of the design wave referredto above for the loading condition being considered,assuming the conditions are not depth-limited.

有效波浪具有相同的周期。

應該留意的是，雖然平均最大波高與

最可能出現的最大波高值很接近，但實際

上最大波高很有可能超過平均最大波

高。例如，利用《B S 6 3 4 9 : P a r t 1》第 2 7 . 3 . 2

節列出的概率公式，可得出在一個波數為

7 5 0的波群裏，其最大波高超出有效波高

2 . 0倍的概率為 2 2﹪，而超出有效波高2 . 1

倍的概率則為 1 0﹪。

4 . 1 2 . 4 受水深限制的情況

關於破碎波和非破碎波在不同水位時

的情況，可以參閱本手冊第3 . 3節。應該

留意的是，有些海事結構的設計波浪會受

到水深限制，在各種荷載條件下的設計波

浪參數，都會和以上章節所載述的不同。

這時，設計便應特別小心，因為這些結構

在其設計使用期內，要承受破碎波的作

用，且極有可能遭受許多與設計波浪類似

的波浪襲擊。在被水深限制的設計裏，設

計波高會與結構前的水深有關，在確定設

計波浪周期以前，應研究所有可能出現的

波浪周期的影響。在受水深限制的環境，

各種荷載條件下的設計波浪周期上限，可

取自以上章節載述的方法，假設不受水深

限制時所得的數值。

45

4.12.5 Calculation of Wave Forces in General

Guidance on the calculation of wave forces is givenin Section 39.4 of BS 6349:Part 1 and Chapter 7,Section III of the Shore Protection Manual (SPM)(CERC, 1984). Reference may also be made toTomlinson (1987) for wave forces on piles and toBruun (1981) for wave forces on vertical walls. As forcurrent loads in Section 4.11, allowance should bemade in calculations for the build-up of marine growthon the structures.

Notes on when to use reflection theory, diffractiontheory and Morison's equation for the assessment ofwave loads are given in Section 39.4.1 ofBS 6349:Part 1. For the range of structure width towavelength where diffraction theory applies, it issuggested that calculations are carried out separately forreflective conditions and using Morison's equation, anda weighted average used for the design wave load. Forsome structures, it will be necessary to separate thestructure into different elements and apply differenttheories to different elements in order to assess the totalwave load on the structure. For a normal pierconsisting of a relatively open concrete deck withtimber fenders suspended on piles, the deck should beconsidered to consist of a solid concrete deck edge,with effective depth to be assessed by the designer, forwhich reflective conditions will apply if the deck lengthis sufficient. Below this solid concrete deck edge, waveloads on the piles and fenders should be assessedseparately using Morison's equation. It shouldnormally be assumed that maximum wave forces onthe deck edge, front piles and fenders can occursimultaneously. However, it should be noted thatmaximum wave forces will not occur simultaneously atall piles in a pile bent.

4.12.6 Wave Forces for Reflective Conditions

For reflective conditions, the method of calculationof wave forces given in Section 39.4.2 ofBS 6349:Part 1 may be used for breaking and non-breaking waves, but care should be taken to cater forpossible high local wave pressures if breaking wavesapply. For non-breaking waves, the method of

4 . 1 2 . 5 一般波浪力的計算

《B S 6 3 4 9 : P a r t 1》第 3 9 . 4節和 《 S h o r e

P r o t e c t i o n M a n u a l》（下稱《 S P M》）

( C E R C , 1 9 8 4 ) 第七章第 3節，載有關於

計算波浪力的指引。計算在樁柱上和直立

牆上的波浪力時，也可參考 T o m l i n s o n

( 1 9 8 7 ) 和B r u u n ( 1 9 8 1 )。跟第 4 . 1 1節中

介紹的水流荷載的計算一樣，計算波浪力

時也應考慮結構上海洋附殖物的影響。

《B S 6 3 4 9 : P a r t 1》第 3 9 . 4 . 1節說明了

在計算波浪荷載時，反射定律、繞射定律

和M o r i s o n方程的適用範圍。當結構寬度

與波長之間的比值在繞射定律適用的範

圍內時，建議分別利用M o r i s o n方程和反

射理論計算，然後再用加權平均數求出設

計波浪荷載。在某些情況下，須將整個結

構分解成不同的部分，分別採用不同的理

論，以便估算作用在結構上的總波浪荷

載。對於一個由樁基混凝土面板結構組成

的普通碼頭，如果在樁上懸掛有護木，則

面板可以視為一整片實體面板的邊緣，其

所處位置的有效深度由設計人員評估，若

面板有足夠的長度，應按反射理論計算。

在這個實體混凝土面板邊緣下面，作用在

樁 柱 和 護 木 上 的 波 浪 荷 載 應 分 別 用

M o r i s o n公式計算。通常可以假設作用在

面板邊緣、前排樁和護木上的最大波浪荷

載同時發生。但應注意的是，最大波浪荷

載不會同時在一個樁群裏的所有樁上出

現。

4 . 1 2 . 6 反射情況下的波浪力

在反射情況下，可以用《B S 6 3 4 9 : P a r t

1》第 3 9 . 4 . 2節載述的方法來計算破碎波

和非破碎波的波浪力。但在計算破碎波的

作用時，應特別注意可能出現較大的局部

波浪壓力 。若是非破碎波，則可使用

《 S P M》第 7 - 1 6 1頁至 7 - 1 8 0頁載述的

46

calculation given in pages 7-161 to 7-180 of the SPMmay be used as an alternative. For the situation referredto above, with a solid concrete deck edge suspendedon piles, it is conservative to assume that the pressuredistribution will be the same as that for a solid verticalwall replacing the piles, and to use either of themethods given above, allowing for a rubblefoundation in place of the piles under the deck, seeFigure 23(a) of BS 6349:Part 1 and Figure 7-98 of theSPM.

For background information on the developmentof the formulae given in Section 39.4.2 ofBS 6349:Part 1 for the calculation of wave forces forreflective conditions, reference may be made to Goda(1974). These formulae were developedexperimentally for both breaking and non-breakingwaves, and calibrated with prototype breakwaters.From the information and conclusions given by Goda(1974), it is suggested that Minikin's method for theassessment of wave forces under reflective conditionsfor breaking waves, as given in pages 7-181 to 7-192 ofthe SPM, should not normally be used for longvertical-face structures, as the predicted wave pressuresappear generally to be far larger than those measured.However, Minikin's method may still be used as anupper bound check on :

(a) wave forces from breaking waves forparticularly critical structures,

(b) local wave pressures, and

(c) for structures of intermediate width, wherediffraction theory applies and both reflectionformulae and the use of Morison's equation willbe required, as explained above.

4.12.7 Wave Forces Using Morison's Equation

For the assessment of wave forces on piles andother elements or structures which extend from waterlevel to sea-bed level, the method of calculation givenin pages 7-101 to 7-160 of the SPM based on

計算方法。如果遇到上面提到的情況，即

樁基上有實體混凝土面板的結構，稍為保

守的方法，是假設作用在其上的壓力分

佈，與作用在以實體直牆代替樁柱時相

同，及用堆石地基代替面板下的樁基，然

後採用上述兩種方法其中之一計算，這方

面可參考《B S 6 3 4 9 : P a r t 1》圖 2 3 ( a ) 和

《 S P M》圖 7 - 9 8。

關於《B S 6 3 4 9 : P a r t 1》第 3 9 . 4 . 2節載

述在反射條件下，計算波浪力的公式，可

參閱G o d a ( 1 9 7 4 ) 的背景資料。這些公式

是通過對破碎波和非破碎波的實驗，並經

過原型防波堤的驗證得出的。按照G o d a

( 1 9 7 4 ) 提供的資料和結論，《 S P M》第 7

- 1 8 1頁至 7 - 1 9 2頁載述的在反射條件下

計算破碎波波浪力的M i n i k i n法，一般不

宜應用在具有較長垂直立面的結構，因為

其估算所得的波浪壓力通常遠遠大於實

測值。然而，M i n i k i n法仍可為以下各項

校核提供上限值﹕

( a ) 破碎波在特別重要的結構上產生的

波浪力，

( b ) 局部波壓力，及

(c) 具有中等寬度的結構，正如前面所

說，在應用繞射定律時，須要同時

利用反射公式和 M o r i s o n 公 式 計

算。

4 . 1 2 . 7 用M o r i s o n公式計算波浪力

計算在樁柱上，及其他由水面伸延至

海床的結構或結構構件上的波浪力，可以

使用《 S P M》第 7 - 1 0 1頁至 7 - 1 6 0頁列

出基於M o r i s o n公式的計算方法。計算只

有部分在水下的結構或結構構件，比如護

木和靠船墩樁帽上的波浪荷載時，建議使

47

Morison's equation may be used. For the assessmentof wave loads on elements or structures such as timberfenders and dolphin pile caps which do not fullyextend from water level to sea-bed level, the followingmethods are suggested :

(a) Maximum total wave force, assuming theelement or structure extends fully from waterlevel to sea-bed level, can be assessed as abovefrom Figures 7-76 to 7-83 of the SPM.

(b) The degree of predominance of inertia/dragforce components can be determined byassessing separately maximum total inertia anddrag forces using Figures 7-71 and 7-72 of theSPM and comparing these forces with themaximum total wave force assessed above. Thedegree of predominance can be checked usingthe criteria given in Section 39.4.4 ofBS 6349:Part 1 relating the width of thesubmerged part of the element or structure tothe orbit width of the water particles at thesurface.

(c) The maximum total wave force on the elementor structure, as a percentage of the maximumtotal wave force assuming the element orstructure extends fully from water level to sea-bed level, can be estimated from Figures 9 to 20.Figures 9 and 10 give the variation of maximumwave force with depth, from 0.4 d above stillwater level to sea-bed level, where d is the depthfrom still water level to sea bed level, for inertiaand drag components, and have been preparedfor linear (Airy) wave theory using equations7.25 and 7.26 from the SPM. Figures 11 to 20give the variation of the percentage of totalmaximum wave force with depth, from waterlevel to sea bed level, for inertia and dragcomponents, and have been prepared directlyfrom Figures 9 and 10. In each case, sets ofcurves are given for five different water levelsfrom 0.4 d above still water level to still waterlevel. The maximum wave crest elevation abovestill water level can be assessed from Figure 7-69of the SPM. The actual water level at the

用下面的方法﹕

( a ) 假設結構或結構構件從水面完全伸

至海床，最大的總波浪力可以按照

上文提到的方法，根據《 S P M》圖

7 - 7 6至圖 7 - 8 3估算。

( b ) 慣性力／拖曳力分量的重要程度可

以 用 下 面 的 方 法 確 定 ， 先 利 用

《 S P M》圖 7 - 7 1和圖 7 - 7 2分別計

算總慣性力和拖曳力，然後與前面

估算出來的最大總波浪力相比較。

其 重 要 程 度 可 以 利 用 《 B S 6 3 4 9 :

Par t 1》第 3 9 . 4 . 4節載述的標準進行

檢驗，該標準與結構或結構構件水

下部分的寬度和水面水質點運動軌

跡的寬度所成的比例有關。

(c) 在結構或結構構件上的最大總波浪

力，與在假設完全從水面延伸至海

床的結構或結構構件上的最大總波

浪力的百分比，可以利用圖9至圖 2 0

估算出來。圖 9和圖 1 0分別顯示波

浪慣性力和拖曳力由靜水位以上

0 . 4 d至海床的變化情況（ d是從靜

水位至海床的深度），它們是根據

線性波理論 ( A i r y ) 利用《 S P M》的

方程 7 . 2 5和方程 7 . 2 6繪製的。圖 1 1

至圖 2 0顯示波浪總慣性力和波浪總

拖曳力的百分比，由水面至海床的

變化情況，它們是根據圖9和圖 1 0

繪出的。每幅圖都顯示出從靜水位

以上 0 . 4 d至靜水位的五個不同水位

的曲線。最大波峰超出靜水位的高

度，可以利用《 S P M》圖 7 - 6 9估

算。結構或結構構件上的實際水

位，可以根據下面的假設估算，即

慣性力佔 1 0 0﹪時對應的是結構或

結構構件上的靜水位，而拖曳力佔

1 0 0﹪時對應的是結構或結構構件

上的最大波峰位。

48

element or structure can be estimated on theassumption that 100% inertia forcepredominance corresponds to still water level atthe element or structure, and 100% drag forcepredominance corresponds to maximum wavecrest level at the element or structure.

(d) The actual maximum total wave force on theelement or structure can be calculated bymultiplying the maximum total wave forceassessed in (a) above by the percentageestimated in (c) above. It should be noted thatthis method is only approximate, the majorlimitation being that the total wave loads arebased on Dean's stream-function theory and thedistribution of wave load with depth is based onlinear (Airy) wave theory. Figure 7-75 of theSPM give details of the regions of validity ofvarious wave theories and can be used to assessthe degree of non-linearity of a wave.

It is particularly important when assessing waveforces for suspended deck structures, where reflectiveconditions may apply for one part and Morison'sequation for another part of the structure, to checkwave forces for different still water levels. The criticalstill water level for wave loads on different elements ofthe structure will not always be the same, and will notalways correspond to the critical water level for waveloads for the structure as a whole.

It should be noted that the formulae given inSection 39.4.4 of BS 6349:Part 1 for the calculation ofwave forces using Morison's equation are derivedfrom linear (Airy) wave theory, and it is recommendedthat these formulae are not directly used for thecalculation of wave forces without first checking thatthis theory applies for the situation being considered.This point is covered by pages 7-101 to 7-112 of theSPM.

For suggested values of inertia and dragcoefficients, reference may be made to Figure 24 andTable 5 of BS 6349:Part 1. It is recommended that thevalues corresponding to moderate marine growth in

( d ) 作用在結構或結構構件上的實際最

大總波浪力可以利用 ( a ) 中估算

出的最大總波浪力與 ( c ) 中估算出

來的百分比相乘求得。應該留意的

是，這種方法只能求得近似值，因

為以上總波浪力的計算是以D e a n

的流函數理論為基礎的，而波浪力

隨 水 深 的 變 化 是 以 線 性 波 理 論

( A i r y ) 為基礎的。《 S P M》圖 7 - 7 5

詳細地顯示了各種波浪理論的適用

範圍，它也可以用來評估波浪的非

線性程度。

估算在承台結構上的波浪力時，有可

能出現一部分結構要應用反射理論，而另

一部分要採用M o r i s o n公式的情況，這時

尤其重要的是要驗算不同靜水位下的波

浪力。計算結構不同部位上的波浪荷載

時，影響最嚴重的靜水位並不一定都相

同，也不一定與對整個結構產生最大波浪

力的水位一致。

應該留意的是，《B S 6 3 4 9 : P a r t 1》第

3 9 . 4 . 4節列出利用M o r i s o n方程來計算

波浪力的公式，是由線性波理論 ( A i r y ) 推

導出來的，因此，在未檢核線性波理論是

否適用以前，這些公式不應被用來計算波

浪力，這一點在《 S P M》 第 7 - 1 0 1頁至 7

- 1 1 2頁已有論及。

《B S 6 3 4 9 : P a r t 1》圖 2 4和表 5載有建

議使用的慣性力系數和拖曳力系數。除特

殊情況外，建議選用圖2 4中屬於中量海洋

附殖物的值。

49

Figure 24 are used unless special circumstances apply.

4.12.8 Wave Uplift Pressures

The standard references given above do not coverwave uplift pressures on suspended deck structures inany detail. For a deck whose soffit is above still waterlevel, uplift pressures are characterised by an initial peakpressure of relatively high magnitude but shortduration, followed by a relatively slowly varying upliftpressure of lower magnitude but of considerableduration, and which is first positive and then negative.Where no other information is available, for normalstructures in open water and for wide structuresfronting sloping rock-armoured seawalls, where it ispossible for still water level to coincide approximatelywith the deck soffit level, the deck should be designedfor a uniform uplift and down drag pressurecorresponding to one half of the maximum waveheight, with an additional uplift pressure correspondingto the average maximum wave height covering a onemetre wide strip parallel to the wave front. Fornarrow structures (width less than 20 metres) frontingsloping rock-armoured seawalls, for all structuresfronting vertical seawalls, and for structures inparticularly exposed locations, the above wavepressures may not be adequate for design, and furtherresearch should be carried out by the designer. Ifpossible, model studies should be carried out. Foradditional information on wave uplift pressures,reference may be made to French (1979), and theHydraulic Research Station (1971a & b).

4.13 Berthing

4.13.1 General

In the course of berthing, loads will be generatedbetween the vessel and the berthing structure from themoment at which contact is first made until the vessel isfinally brought to rest. The magnitude of the loads willdepend, not only on the size and velocity of the vessel,but also on the nature of the structure, including anyfendering, and the degree of resilience it presents underimpact.

4 . 1 2 . 8 波浪浮托力

前述的參考文獻，並未有論及承台結

構所承受的波浪浮托力。對於一塊底面高

於靜水位的面板，浮托力的特點是在波峰

出現時壓力較大，而持續時間較短；隨後

壓力逐漸變小，而持續時間較長，初時為

正壓力，後來變為負壓力。在沒有其他可

利用的資料時，對於那些在開敞水域中的

一般結構和斜坡式塊石護面海堤前面的

較寬結構，如果靜水位有可能出現與面板

底高程接近的情況時，面板設計便應考慮

一個平均分佈的浮托力和下拽力（與最大

波高的一半相對應），同時還伴隨一個附

加浮托力，（該浮托力與平均最大波高相

對應），其範圍寬一米及與波鋒平行。對

於那些位於斜坡式塊石護面海堤前面較

窄（寬度小於 2 0米）的結構、直立式海堤

前面的結構，以及在特別開敞水域的結

構，上文提到的波浪壓力計算方法可能並

不足夠，設計人員應作進一步研究。如有

可能，應進行模型試驗。關於波浪浮托力

的其他資料，可參考 F r e n c h ( 1 9 7 9 ) 及

H y d r a u l i c R e s e a r c h S t a t i o n ( 1 9 7 1 a 及

b )。

4 . 1 3 靠泊

4 . 1 3 . 1 概述

在船舶靠泊過程中，船舶和靠泊結構

之間會產生荷載。這一荷載從船與結構開

始接觸時，一直持續到船舶完全停止。荷

載的大小不僅取決於船舶的大小和速

度，同時也取決於結構本身的特性，包括

其護舷設備及結構在被撞時的彈性表

現。

傳遞到結構上的靠泊荷載，包括垂直

50

Berthing loads transmitted to a structure compriseimpact loads normal to the berthing face and frictionloads parallel to the berthing face. The impact loadnormal to the berthing face depends upon the berthingenergy and the load/deflection characteristics of thevessel, structure and fender system. The design frictionload parallel to the berthing face should be taken as thecoefficient of friction between the two faces in contactmultiplied by the maximum design impact load.Guidance on this coefficient is given in Table 3 ofBS 6349:Part 4 (BSI, 1985a).

4.13.2 Assessment of Energy to Be Absorbed

A method of assessing the total amount of energyto the absorbed, either by the fender system alone orby a combination of the fender system and thestructure itself for a structure with some flexibility, isgiven in Section 4.7 of BS 6349:Part 4. For thisassessment, the eccentricity coefficient can normally betaken as 0.5, the softness coefficient as 1.0, and theberth configuration coefficient as 0.8 and 1.0 for a solidquay wall and open piled jetty respectively. The designvelocity of the vessel normal to the berth depends onthe vessel size and type, frequency of arrival, possibleconstraints on movement approaching the berth, andwave, current and wind conditions likely to beencountered at berthing. Where no other informationis available, for the Normal Loading Conditionsreferred to in Section 4.2, the following transversevelocities may be used as a guide :

Vessel Displacement Transverse Velocity

Under 100 t 0.40 m/s100 to 200 t 0.35 m/s200 to 500 t 0.30 m/s500 to 1500 t 0.25 m/s

The transverse velocities suggested above relate tostructures located at sites with normal exposure toenvironmental conditions without excessive frequencyof use, and assume that berthing may continue after theraising of Tropical Cyclone Signal No. 3, and for the

於靠泊面的撞擊荷載和平行於靠泊面的

摩擦荷載。撞擊荷載強弱，取決於靠泊時

船舶具有的能量和船舶、結構及護舷系統

的荷載／變位特性。設計摩擦荷載，應為

接觸面間的摩擦系數乘以最大設計撞擊

荷載。《B S 6 3 4 9 : P a r t 4》 ( B S I , 1 9 9 4 ) 表

3提供了關於選擇摩擦系數的指引。

4 . 1 3 . 2 吸收能量的估算

《B S 6 3 4 9 : P a r t 4》第 4 . 7節載述了估

算被吸收能量總額的方法，這些能量可能

被護舷系統獨立吸收，也可能被護舷系統

和具有彈性的結構共同吸收。在估算時，

偏心系數通常可取 0 . 5，柔度系數可取

1 . 0，靠泊實體裝卸堤和透空式樁基突堤

的形狀系數可分別取 0 . 8和 1 . 0。船舶的設

計靠泊速度決定於船舶種類和大小、船舶

到岸的頻率、船舶接近碼頭時的操作情

況，以及在靠泊時可能出現的波浪、水流

和風等環境條件。當沒有其他可用資料

時，在第 4 . 2節提到的正常荷載條件下，

可採用下列橫向速度 ：

船舶的排水量 橫向速道

1 0 0 t 以下 0 . 4 0 m / s

1 0 0 至 2 0 0 t 0 . 3 5 m / s

2 0 0 至 5 0 0 t 0 . 3 0 m / s

5 0 0 至 1 5 0 0 t 0 . 2 5 m / s

以上列出的橫向速度，適用於暴露在

一般環境條件下，且使用率正常的結構，

同時還假設在三號熱帶氣旋信號懸掛以

後，及八號熱帶氣旋信號懸掛後的最初數

小時內，船舶的靠泊作業未因而中止。如

要採納這些速度作詳細設計，應先徵詢海

事處、其他使用者或渡輪公司。

51

first few hours after the raising of Tropical CycloneSignal No. 8. Before any velocity is finally adopted fordetailed design, advice should be sought from theDirector of Marine and other users or ferry operatorsas appropriate.

For Accident Loading Conditions, generalcomments are given in Section 4.2.4. The vesseldisplacement and transverse velocity for suchconditions must be decided by the designer for theindividual structure being considered, but as a generalrule the total energy to be absorbed for accidentloading should be at least 50% greater than for normalloading. For particularly critical structures or forstructures with expected heavy use and exposure, thismay need to be increased to 100%.

4.13.3 Berthing Reactions

Berthing reactions to be taken by the structure canbe assessed from the manufacturer'sreaction/deformation/energy curves once the type offender to be used has been determined. Forinformation on types of fenders, see BS 6349:Part 4,Quinn (1972) and manufacturers' catalogues. Theultimate energy capacity of each fender should ingeneral be at least 50% greater than that calculated fornormal loading conditions to allow for accidentaloccurrences such as vessel engine failure, breaking ofmooring or towing lines, sudden changes of wind orcurrent conditions, and human error. Because of thenon-linear energy/deflection and reaction/deflectioncharacteristics of most fender systems, the effects ofboth normal and abnormal impacts on the fendersystem and berth structures should be examined.

4.14 Mooring

Mooring loads comprise those loads imposed on astructure by a vessel tied up alongside, both throughcontact between the vessel and structure or itsfendering system, and through tension in mooringropes. These loads are principally caused by winds and

第 4 . 2 . 4節已論述了意外荷載條件，在

這種條件下的船舶排水量和橫向速度，必

須由設計人員根據結構具體情況確定。但

是，一般在意外荷載條件下，須吸收的總

能量，至小應比正常荷載條件下高出 5 0

﹪，而對特別重要，或使用率高、暴露程

度較大的結構，所要吸收的能量可能要比

正常荷載條件下高出 1 0 0﹪。

4 . 1 3 . 3 靠泊反力

在確定護舷類型後，便可根據生產商

提供的反力／變形／能量曲線，估算結構

對靠泊的反作用力。有關護舷類型的資

料，可查閱《B S 6 3 4 9 : P a r t 4》，Q u i n n

( 1 9 7 2 ) 和生產商的產品目錄。一般來說，

護舷所能承受的最大能量，至少應比正常

荷載條件下計算出來的要求高出 5 0﹪，以

顧及船舶發動機故障、繫泊纜繩或牽引纜

繩斷裂、風或海浪條件突然變化，以及人

為失誤等意外事故的發生。由於大多數護

舷系統在能量／變位和反力／變位的關

係都是非線性的，因此在護舷系統和靠泊

結構上的撞擊，無論是正常或非正常的，

其影響都應加以檢驗。

4 . 1 4 繫泊

繫泊荷載是由停靠在海事結構旁的船

舶施加到結構上，包括通過船舶與結構或

其護舷系統的直接接觸，和通過纜繩的張

拉而產生的荷載。它們主要由風和水流引

起，而在較開敞水域，也會由波浪引起。

對於本手冊涉及的普通海事結構，和較小

的船隻 (排水量少於 1 5 0 0公噸），通常不

52

currents and, in more exposed locations, by waves.For the normal structures covered by this Manual andthe relatively small vessels considered for berthing(displacement generally less than 1500 t), it is notusually necessary to carry out specific calculations todetermine the probable maximum mooring loads, asthese loads generally will not be critical for structuraldesign.

Mooring bollard locations and normal maximumworking loads should be agreed with the Director ofMarine, user departments and the ferry operators asappropriate. For Normal Loading Conditions,mooring loads may be assumed to be equal to thenormal maximum bollard working loads. Allowanceshould be made for the mooring lines not beinghorizontal; if no other information is available, amaximum angle to the horizontal of 30° (up anddown) may be assumed. The direction of eachmooring load should be taken as that having the mostadverse effect on the structure, and in general it shouldbe assumed that all mooring loads on a structure canact simultaneously.

Because of the relatively small vessels consideredfor berthing, the loads imposed on a structure by directcontact between the vessel and the structure, or itsfendering system, need not be considered for NormalLoading Conditions, as these will usually be minor inrelation to the combined effects of other imposedloads such as those from winds, currents, waves andberthing.

Where it is considered necessary to calculate theforces acting on moored vessels in order to checkbollard loads or loads imposed directly by vessels on astructure, reference may be made to BS 6349:Parts 1& 4, Quinn (1972) and Bruun (1981).

4.15 Earthquakes

For the marine structures covered by this Manual,seismic forces in Hong Kong can be assumed to beminor in relation to the combined effects of other

須估算其可能出現的最大繫泊荷載，因為

這些荷載一般對所設計的結構並不構成

嚴重影響。

確定繫船柱的位置和正常最大工作荷

載前，應先徵詢海事處、使用部門和渡輪

公司。在正常荷載條件下，可以假設繫泊

荷載與繫船柱的正常最大工作荷載相

同。須考慮繫船纜繩並非水平的情況；如

果沒有其他可用資料時，可以假設纜繩與

水平面的最大夾角為3 0 o（可在水平面以

上，也可在水平面以下），而每一個繫泊

荷載都應假設在對結構產生最不利影響

的方向。一般來說，應該假設在結構上的

所有繫泊荷載，都可能同時出現。

如果靠泊船隻相對較小，則船舶與結

構或護舷系統發生直接接觸而作用於結

構上的荷載，在正常荷載條件下不須考

慮，因為這些荷載與由風、水流、波浪和

靠泊所產生的綜合荷載效應，相比是很小

的。

在某些情況下，須計算作用在已繫泊

的船舶上的荷載，以便檢驗繫船柱上的荷

載和直接在結構上的荷載，這方面可參考

《B S 6 3 4 9 : P a r t 1》及《B S 6 3 4 9 : P a r t 4》、

Q u i n n ( 1 9 7 2 ) 和B r u u n ( 1 9 8 1 )。

4 . 1 5 地震

與其他荷載的綜合效應比較，香港地

震力對本手冊涉及的海事結構的影響，可

說十分輕微，因此，縱使未有經過驗算，

也可以假設這些結構能抵受地震力的作

用。G C O ( 1 9 9 1 ) 載有關於地震情況的資

料。

53

imposed loads, and it can be assumed that thesestructures can adequately withstand such forces withouta specific check. Further information on seismicity maybe obtained from GCO (1991).

4.16 Movements and Vibrations

For guidance on movements and vibrations,reference may be made to Section 47 ofBS 6349:Part 1. For the marine structures covered bythis Manual and the relatively shallow-water depthsnormally applying, movement and vibration problemsshould not be expected and usually can be effectivelyignored. Movements between different parts ofstructures, and between new and existing structures,should be assessed in the usual way in order to fix jointsizes and locations. Where vessel berthing occurs,movements of flexible and even relatively inflexiblestructures can be important in assisting with energyabsorption.

4 . 1 6 位移和振動

關於位移和振動方面的指引，可參考

《B S 6 3 4 9 : P a r t 1》第 4 7節。本手冊內提

及的海事結構如果位於較淺水域，位移和

振動的問題通常不會出現，因而可以不予

考慮。結構不同部分之間和新舊結構之間

的位移，應根據常用的方法估算，以便確

定接縫的大小和位置。船舶靠泊時，柔

性、甚至柔性相對地較低的結構的位移，

都是吸收能量的重要因素。

54

55

5. DESIGN OF FOUNDATIONS

5.1 Introduction

This Chapter gives guidance on the design offoundations for marine structures and covers suchaspects as site investigation, soil properties andfoundations. The structural design of piles is coveredby Chapter 6. Guidance on the design of sheet piled,gravity and rubble structures is given in Chapters 7, 8and 9 respectively, although many comments in thisChapter apply also to these types of structures.

The structure and its foundation should be designedso that, during its intended life, foundationdisplacements and movements are kept within thelimits that the structure can tolerate without affecting itsstructural integrity and functional capability.Consideration of the interaction between structure andsoil, and the need to limit foundation movements, maydetermine the most suitable type of structure for aparticular location. The performance of the structureand the sea bed should be considered together.BS 8004 (BSI, 1986) relates to the foundations ofbuildings and general engineering structures, but manyof the recommendations are equally applicable tomarine structures. One particularly important aspect tobe investigated for foundations for marine structuresrelates to the stability of the adjacent sea bed underwave and current action, and the possibility of scourand undermining. It is also necessary to check theoverall stability of marine structures against potentialshear failure in the supporting ground.

It is recommended that global factors of safetyshould be used when designing foundations for marineworks. Loads used should be unfactored valuescovered by Chapter 4, with no allowance for partialsafety factors. When considering the interactionbetween structure and soil, all of the appropriateloading conditions described in Section 4.2 should beexamined. If it is expected that other loadingconditions could be critical, they should also beinvestigated. Guidance on factors of safety is given inSection 5.4 for piled foundations and in later sections

5 . 地基設計

5 . 1 概述

本章為海事結構的地基設計提供指

引，內容包括現場勘測、土壤特性及地基

等。樁柱結構的設計，將在第六章論述。

第七、八及九章載有關於板樁結構、重力

式結構及堆石防波堤結構的設計指引；本

章部分內容亦適用於這些海事結構。

結構及其地基設計，應使其在設計使

用期內，地基位移保持在容許的限度內，

不會影響結構的完整性和使用功能。結構

和海床的特性，結構和土壤的相互作用，

及限制地基位移等因素，會決定某一特定

場地的最適當結構類型。《B S 8 0 0 4》 ( B S I ,

1 9 8 6 ) 論述了建築物和一般工程結構的

地基，其中很多建議也同樣適用於海事結

構。考慮海事結構的地基時，須特別評估

其附近的海床在波浪和水流作用下的穩

定性，和可能出現的水流 刷與淘空。同

時，還要檢查海事結構的承載地基，在防

止潛在的剪切破壞方面的總體穩定性。

設計海事結構的地基時，建議使用綜

合的安全系數。所用荷載應為第四章所述

的基本荷載值，毋須加上分項安全系數。

在考慮結構和土壤的相互作用時，須檢視

第 4 . 2節所述的所有適用荷載條件。如果

認為其他某些荷載條件也有嚴重影響，則

這些荷載條件亦應予以考慮。第 5 . 4節載

有關於樁柱地基安全系數的指引，而後面

的章節會論述其它類型的地基。

56

for other types of foundations.

5.2 Site Investigations

Reference should be made to Geoguide 2 (GCO,1987) for guidance on good site investigation practiceand Geoguide 3 (GCO, 1988) for guidance ondescription of rocks and soils in Hong Kong.Chapter 14 of Geoguide 2, which covers groundinvestigations over water, is particularly relevant,together with Sections 10.7.7 and 33.3. Furtherguidance relevant to marine situations is given inSection 49 of BS 6349:Part 1 (BSI, 1984a).

5.3 Properties of the Ground

Information on average properties for preliminarydesign and the selection of parameters for workingdesign is given in Chapter 50 of BS 6349:Part 1.Further guidance on the properties of the ground inrelation to various structures is given in BS 8004 (BSI,1986).

5.4 Piled Foundations

Guidance on the design of piled foundations isgiven in BS 8004 and Tomlinson (1987). Sections6.12.4, 6.12.5, 6.12.6, 6.12.8 and 6.12.12 ofBS 6349:Part 2 (BSI, 1988) are also relevant.

For any pile, the working load should be not greaterthan the ultimate bearing or pull-out capacity, asappropriate, divided by a factor of safety. Whereverpossible and practical, ultimate bearing or pulloutcapacities should be assessed from loading tests.Where ultimate bearing or pullout capacities have beenassessed from a number of loading tests, a globalfactor of safety of 2.0 is recommended. Where onlyone or a small number of loading tests has been carriedout, an increase in the factor of safety should beconsidered. Where no loading test has been carriedout, and ultimate bearing or pullout capacity has beenassessed from application of a dynamic driving

5 . 2 現場勘測

《G e o g u i d e 2》 ( G C O , 1 9 8 7 ) 提供了現

場勘測工作的指引，而《 G e o g u i d e 3》

( G C O , 1 9 8 8 ) 描述了香港的岩石和土壤

特性。它們都可作為現場勘測的參考，其

中《 G e o g u i d e 2》第 1 4章、第 1 0 . 7 . 7節

及 3 3 . 3節論述水上地質勘測，尤為適用。

《B S 6 3 4 9 : P a r t 1》 ( B S I , 1 9 8 4 a ) 第 4 9

節也載有適用於海事工程的指引。

5 . 3 地質特性

《B S 6 3 4 9 : P a r t 1》 第 5 0章載有一般

的土質特性，可用於初步設計，此外也有

選 擇 實 質 設 計 參 數 的 有 關 資 料 。

《B S 8 0 0 4》 ( B S I , 1 9 8 6 ) 提供和各種結

構有關的土質特性的具體指引。

5 . 4 樁柱地基

《B S 8 0 0 4》 和T o m l i n s o n ( 1 9 8 7 ) 載

有設計樁柱地基的指引。《B S 6 3 4 9 : P a r t

2 》 ( B S I , 1 9 8 8 ) 第 6 . 1 2 . 4 、 6 . 1 2 . 5 、

6 . 1 2 . 6、6 . 1 2 . 8和 6 . 1 2 . 1 2節也有適用的指

引。

任何樁柱的工作荷載，均不應超過極

限承壓力或極限抗拔力除以安全系數所

得的值。如有可能，應通過荷載試驗，確

定其極限承壓力和極限抗拔力。如極限承

壓力和極限抗拔力根據大量荷載試驗而

訂定，建議綜合安全系數取2 . 0；如只根

據一個，或少數荷載試驗訂定，則應將安

全系數提高；如未有進行任何荷載試驗，

而是通過動態打樁公式、應力波分析、土

壤試驗或綜合應用這些方法來訂定，則建

議綜合安全系數取 3 . 0。如覆打時發現阻

力減少，或未運用上述綜合方法，或得出

不一致的結果，均應將安全系數提高。

57

formula, use of stress wave analysis, soil tests, orcombination of these, a global factor of safety of 3.0 isrecommended. Where reduced resistance has beenfound during redriving, or where no combinationreferred to above has been used, or where inconsistentresults have been found, an increase in the factor ofsafety should be considered.

The working load for a pile may be taken as themaximum of the computed axial bearing and pulloutloads for the various loading conditions referred to inSection 4.2 multiplied by the following factors:

Loading Condition Factor

Normal 1.00Extreme 0.80Temporary 0.80Accident 0.75

It should be noted that the above factors imply anacceptable level of overstress compared with normalconditions of 25% for extreme and temporaryconditions and 33.3% for accident conditions.

There are a number of definitions for the ultimatecapacity of piles. However, for a loading test carriedout in accordance with the General Specification forCivil Engineering Works (Hong Kong Government,1992a), the ultimate bearing or pullout capacity of a pilemay be taken as the maximum test load for which thepermanent settlement or upward movement, oncompletion of the load test, is D/50 or 8 mm,whichever is the lesser, where D is the diameter of acircular pile or the least dimension of a rectangular pile.

採用第 4 . 2節提到的各種荷載條件，算

出的最大軸向承壓力和抗拔力再乘以以

下系數後，可作為樁柱的工作荷載。

荷載條件 系數

正常 1 . 0 0

極端 0 . 8 0

臨時 0 . 8 0

意外 0 . 7 5

應用上述系數時，其實是容許一定程

度的超載。與正常荷載條件相比，在極端

和臨時荷載條件下，容許的超載為2 5﹪；

在意外荷載下，則為 3 3 . 3﹪。

樁柱的極限承壓力，可有不同定義。

然而，若按照《G e n e r a l S p e c i f i c a t i o n f o r

C i v i l E n g i n e e r i n g W o r k s》 ( H o n g K o n g

G o v e r n m e n t , 1 9 9 2 a ) 進行荷載試驗，則

樁柱的極限承壓力或極限抗拔力，可界定

為最大試驗荷載；該荷載使試驗結束後的

永久沉降或向上位移為D / 5 0或 8毫米，取

其最小值，其中D代表圓樁的直徑或方樁

的最小尺寸。

58

59

6. DESIGN OF SUSPENDED DECK STRUCTURES

6.1 Introduction

This Chapter gives guidance on the design ofsuspended deck structures, including dolphins. Itcovers structures of concrete, steel and a combinationof these materials. The design of sheet pile and gravitystructures located immediately behind marginal quays,and of rubble mound structures located undermarginal quays, is covered in Chapter 7, 8 and 9respectively.

Comments on general design methods are given inSection 6.10 of BS 6349:Part 2 (BSI, 1988). Particularnote should be taken of Clause 6.10.3.1 ofBS 6349:Part 2, which relates to the distribution oftransverse loads.

6.2 Load Combinations and Factors

The structure should be designed to resist allcombinations of loads which may realistically beassumed to act on the structure simultaneously, eitherdirectly on the superstructure or indirectly via the piles.As a minimum, the load cases referred to in Section 4.2should be considered. Guidance on nominal loads forboth limit state and working stress design methods aregiven in Sections 4.3 to 4.16.

For limit state design, it is recommended that theload factors given in Clause 6.11.4.2 ofBS 6349:Part 2 are adopted. It is suggested that, forAccident Loading Conditions (see Section 4.2.4), thepartial load factors given in Table 2 of BS 6349:Part 2for Extreme Loading Conditions (Section 4.2.2)should be used.

For working stress design, under Extreme andTemporary Loading Conditions (Sections 4.2.2 and4.2.3), it is suggested that normal permissible workingstresses may be increased by 25%; under AccidentLoading Conditions, an allowable increase of 33.3% is

6 . 承台結構的設計

6 . 1 概述

本章提供設計承台式碼頭結構的指

引，靠船墩的設計也包括在內。其中涉及

混凝土結構、鋼結構及此類材料的混合結

構。順岸式碼頭後的板樁和重力式結構的

設計，及順岸式碼頭下面的堆石結構的設

計，分別在第七、八及九章論述。

《B S 6 3 4 9 : P a r t 2》 ( B S I , 1 9 8 8 ) 第 6 . 1 0

節載有一般的設計方法。應特別注意

《B S 6 3 4 9 : P a r t 2》第 6 . 1 0 . 3 . 1節，此節

論述橫向荷載的分佈。

6 . 2 荷載組合與系數

結構的設計，應能承受可能同時作用

的所有荷載組合，包括直接作用在上蓋結

構與間接經樁柱傳送的荷載。第 4 . 2節提

到的荷載組合可視為最低的設計標準。第

4 . 3節至 4 . 1 6節載有關於極限狀態設計法

和許用應力設計法的額定荷載的指引。

應用極限狀態設計法時，建議採用

《B S 6 3 4 9 : P a r t 2》 第 6 . 1 1 . 4 . 2節列出的

荷載系數。在意外荷載條件下（見第 4 . 2 . 4

節），建議採用《B S 6 3 4 9 : P a r t 2》表 2

列出相當於極端荷載條件（見第 4 . 2 . 2

節）的分項荷載系數。

應用許用應力設計法時，則建議在極

端和臨時荷載條件下（見第 4 . 2 . 2節 和

4 . 2 . 3節），一般容許應力可提高2 5﹪；

在意外荷載條件下，可提高3 3 . 3﹪。詳情

可參閱《B S 6 3 4 9 : P a r t 2》第 6 . 1 1 . 4 . 3節。

60

suggested. Reference is made to Section 6.11.4.3 ofBS 6349:Part 2.

For all loading conditions other than AccidentLoading Conditions, the partial safety factors formaterials given in Table 2.2 of BS 8110:Part 1 (BSI,1985a) should be used. For accident loadingconditions, the factors for concrete in flexure, and forsteel reinforcement, may be reduced from 1.5 to 1.3and from 1.15 to 1.0 respectively.

6.3 Superstructure

It is recommended that BS 8110:Part 1 shouldform the basis for the design of concrete deckstructures, using the partial load factors referred to inSection 6.2. For steel deck structures, the use ofBS 449:Part 2 (BSI, 1969) is recommended, withincreased permissible stresses for certain loadingconditions as suggested in Section 6.2.

6.4 Piles

For general comments on the design of piles, seeSection 6.12 of BS 6349:Part 2. It is recommendedthat limit state design is used for concrete piles, andworking stress design for steel piles, as for concrete andsteel deck structures in Section 6.3 above, using similarload factors and increased permissible stresses asappropriate.

6.5 Durability

6.5.1 Reinforced and Prestressed Concrete

General requirements for reinforced or prestressedconcrete can be found in Section 11.4.

Compliance with the bar spacing rules given inSection 3.12.11 of BS 8110:Part 1 will generallyensure that, for the most severe combination of loadsunder the serviceability limit state, crack widthsanywhere in a concrete structure will be limited to amaximum of 0.3 mm. For concrete within the

除意外荷載條件外，所有荷載條件均

應使用《B S 8 1 1 0 : P a r t 1》 ( B S I , 1 9 8 5 a )

表 2 . 2列出的材料分項安全系數。在意外

荷載條件下，受彎混凝土和鋼筋的系數可

分別由 1 . 5減為 1 . 3及由 1 . 1 5減為 1 . 0。

6 . 3 上蓋結構

混 凝 土 面 板 結 構 的 設 計 ， 應 以

《B S 8 1 1 0 : P a r t 1》 為依據，並應使用第

6 . 2節所述的分項荷載系數。鋼面板結構

的設計，建議採用《B S 4 4 9 : P a r t 2》 ( B S I ,

1 9 6 9 ) 的標準，並在某些荷載條件下，如

第 6 . 2節所述，提高容許應力。

6 . 4 樁柱

有關樁柱的設計概述見《B S 6 3 4 9 : P a r t

2》 第 6 . 1 2節。樁柱的設計方法，應與第

6 . 3節所述混凝土與鋼面板結構相同，即

採用相同的荷載系數，用極限狀態設計法

設計混凝土樁，和採用較高的容許應力，

用許用應力設計法設計鋼樁。

6 . 5 耐久性

6 . 5 . 1 鋼筋混凝土和預應力鋼筋混凝土

關於鋼筋混凝土或預應力鋼筋混凝土

的一般要求見第 1 1 . 4節。

若按照《 B S 8 1 1 0 : P a r t 1》第 3 . 1 2 . 1 1

節的規定佈筋，則在耐久性極限狀態的最

大荷載組合下，混凝土結構任何部位的最

大裂縫寬度，一般不會超過0 . 3毫米。位

於水位變動和浪濺區的混凝土，在典型的

平均荷載長期作用下，裂縫寬度應限制在

0 . 1毫米。長期作用在結構各構件上的典

61

intertidal and splash zones, it is recommended thatcrack widths under typical average long term loadingconditions should be limited to 0.1 mm. The typicalaverage long term loading conditions for each elementof a structure will depend on the type of structure andits use, and must be assessed by the designer for eachcase. As a guide, for the normal types of suspendeddeck structure covered by this Manual, typical averagelong term loading should cover full dead andsuperimposed dead loads, combined with 50 to 75%of full live loads, using nominal or characteristic loadsin each case. Normally, berthing, mooring, wind andwave loads need not be considered, because of theirrelatively short duration. For the assessment of crackwidths, reference can be made to Section 3.8 ofBS 8110:Part 2 (BSI, 1985b).

6.5.2 Steelwork

Guidance on corrosion protection and allowancefor metal losses can be found in Chapter 11.

型平均荷載，與結構型式及其用途有關，

須由設計人員按個別情況估算。對於本手

冊提到的一般承台式結構，典型的長久平

均荷載應包括恒載，附加恒載及5 0﹪到 7 5

﹪的活荷載，按情況採用額定荷載或特徵

荷載。靠泊力、繫泊力、風荷載和波浪荷

載的作用時間相對較短，因此通常都無須

考慮 。至於裂縫寬度的評估 ，可參考

《B S 8 1 1 0 : P a r t 2》 ( B S I , 1 9 8 5 b ) 第 3 . 8

節。

6 . 5 . 2 鋼結構

有關銹蝕防護和預留銹蝕量的指引，

載於第 1 1章。

62

63

7. DESIGN OF SHEET PILEDSTRUCTURES

7.1 General

General information on the design of sheet piledstructures is given in Section 51 of BS 6349:Part 1(BSI, 1984a), and information on the design of sheetpiled walls in quay and jetty construction is given inSection 4 of BS 6349:Part 2 (BSI,1988). Referencemay also be made to GCO (1990) and to BS 8002(BSI, 1994c).

7.2 Corrosion Protection

For steel sheet piled structures, the basic commentsregarding corrosion loss and protection given inSection 11.5.2 for steel suspended deck structuresapply. Full corrosion protection is recommendedabove sea bed level for normal permanent structures.For temporary structures, with a design life not greaterthan ten years, where there is no corrosion protection,an allowance for corrosion loss of 0.5 mm/year persurface is suggested for the zone between sea bed leveland Chart Datum. Above Chart Datum, full corrosionprotection is strongly recommended, even fortemporary structures.

7 . 板樁結構的設計

7 . 1 概述

《B S 6 3 4 9 : P a r t 1》 ( B S I , 1 9 8 4 a ) 第 5 1

節，載有關於設計板樁結構的常用資料；

《B S 6 3 4 9 : P a r t 2》 ( B S I , 1 9 8 8 ) 第 4節，

載有關於設計板樁裝卸堤和突堤的資

料。此外，還可參考G C O ( 1 9 9 0 ) 和

《B S 8 0 0 2》 ( B S I , 1 9 9 4 c )。

7 . 2 銹蝕防護

第 1 1 . 5 . 2節論述鋼板承台式結構的銹

蝕損壞及其防護，該部分亦同樣適用於板

樁結構。至於一般的永久性結構，海床以

上的部分應進行全銹蝕防護。無銹蝕防護

而設計使用期不超過十年的臨時結構，建

議在海床和海圖基準面之間部分的預留

銹蝕量為每面每年 0 . 5毫米。海圖基準面

以上部分，建議進行全銹蝕防護，即使是

臨時結構，也不例外。

64

65

8. DESIGN OF GRAVITY STRUCTURES

8.1 General

Information on the design of gravity walls in quayand jetty construction is given in Section 5 ofBS 6349:Part 2 (BSI, 1988). Reference may also bemade to ISE (1951), which is currently under revisionas BS 8002 (BSI, 1994c), and Geoguide 1 (GEO,1993). Certain aspects of the design of concreteblockwork walls, which are the most commonlyconstructed gravity structures in Hong Kong, areexpanded upon in this Chapter.

8.2 Concrete Blockwork Walls

8.2.1 General

Whenever possible, checks against soil shear failureshould be based on ground investigation in accordancewith Geoguide 2 (GCO, 1987) and tests onconstruction materials.

Where soil properties have been tested inaccordance with Geoguide 2, minimum factors ofsafety against soil shear failure of 1.3 for NormalLoading Conditions and 1.2 for Extreme LoadingConditions are recommended. For overturning, underNormal Loading, a factor of safety of 2.0 isrecommended provided that the resultant is within themiddle third of the base width for the interfacebetween the blocks and the rubble foundation whentransient loads are ignored. For the interface betweenthe blocks, the resultant force may lie within the middlehalf. For Extreme Loading, the resultant may falloutside the middle third provided the minimum factorof safety against overturning is 1.5. Recommendedminimum factors of safety against sliding of the base,or at horizontal block interfaces, are 1.75 for NormalLoading and 1.5 for Extreme Loading Conditions.

For information on coefficients of friction, tosupplement that given in Sections 5.3.1.4 and 5.4.8.5of BS 6349:Part 2, see Table 7-16 of the Shore

8 . 重力式結構的設計

8 . 1 概述

《B S 6 3 4 9 : P a r t 2》 ( B S I , 1 9 8 8 ) 第 5

節載述了設計重力式裝卸堤和突堤的資

料。此外，亦可參考《 B S 8 0 0 2》 ( B S I ,

1 9 9 4 c ) 和《G e o g u i d e 1》 ( G E O , 1 9 9 3 )。

本章闡述香港最常用的重力式結構，混凝

土方塊牆的設計要點。

8 . 2 混凝土方塊牆

8 . 2 . 1 概述

進行土壤抗剪切破壞驗算時，應盡可

能參照按《G e o g u i d e 2》( G C O , 1 9 8 7 ) 完

成的地質勘測資料，和施工材料的試驗結

果。

如果根據《G e o g u i d e 2》進行了土壤

特性試驗，建議在正常荷載條件下，土壤

抗剪切破壞的最低安全系數取 1 . 3；在極

端荷載條件下，最低安全系數取 1 . 2。驗

核在正常荷載條件下抗傾覆情況時，若省

略瞬時荷載後，方塊和堆石基床交界處的

合力作用點，落在地基寬度中間三分之一

範圍內，建議安全系數取 2 . 0。各方塊層

間的合力作用點，可落在中間二分之一範

圍內。在極端荷載條件下，合力作用點可

以落在中間三分之一範圍以外，但這時最

小抗傾覆安全系數須取 1 . 5。方塊牆的底

部或方塊層間的水平交界處，在正常荷載

條件下的抗滑動安全系數，建議取1 . 7 5；

在極端荷載條件下，則取 1 . 5。

《 B S 6 3 4 9 : P a r t 2》 第 5 . 3 . 1 . 4 節 和

5 . 4 . 8 . 5節載有關於摩擦系數方面的資

料 ； 《 S h o r e P r o t e c t i o n M a n u a l 》

66

Protection Manual (CERC,1984) and Appendix B,Part 3, of Bruun (1981). For friction between twoprecast concrete blocks and between a precast concreteblock and a levelled rubble foundation, a coefficient offriction of 0.6 is suggested.

For guidance on the stability against wave attack ofrubble foundations for concrete blockwork walls,reference should be made to Chapter 9.

8.2.2 Ground Water Levels and Profiles

The situation with a wave trough at the seawallcombined with the expected range of still water levelshould be investigated for both Normal and ExtremeLoading Conditions. The ground water levelimmediately behind the concrete block seawall can beassumed to be the same as still water level. The groundwater profile in the fill behind the seawall should beassessed, taking into account expected fill permeability,tidal lag and the flow of surface or subsoil water fromlandward sources. As a guide, for normal conditions,where the land behind the seawall is not paved andwhere the fill is highly variable, a ground water profilerising from behind the seawall at a slope of one verticalto two horizontal to a level of 0.5 m above MHHW issuggested; for extreme conditions, a slope of onevertical to one horizontal rising to ground level isconsidered reasonable.

8.2.3 Consideration of Settlement

For all concrete blockwork walls, the totalsettlement expected during the design life of thestructure should be assessed to ensure that this isacceptable in relation to the proposed use. In manycases, the depth of dredging and width of dredgedtrench for a rubble foundation of a concreteblockwork wall will be determined by the need to limitlong term settlement rather than the need to have anadequate factor of safety against a deep rotationalfailure in the underlying soil.

( C E R C , 1 9 8 4 ) 表 7 - 1 6和B r u u n ( 1 9 8 1 )

第三部分附錄B也有補充資料。預製混凝

土方塊之間，及預製混凝土方塊和整平過

的堆石基床之間的摩擦系數建議取 0 . 6。

關於混凝土方塊牆的堆石基床在波浪

擊下的穩定性問題，可參考第九章。

8 . 2 . 2 地下水的水位和分佈

有關正常和極端荷載條件下的查驗，

均須包括海堤處於波谷位置，而遇上任何

可能出現的靜水位時的情況。緊接混凝土

方塊海堤後面的地下水位則可假定與靜

水位相同。估量海堤後回填土的地下水位

時，要預計回填土的透水性、潮汐滯後時

間、地表徑流和陸向來的地下水。在正常

荷載條件下，如果海堤後的土地未有鋪

面，且回填土的種類變化很大時，海堤後

的地下水位可假設以 1（垂直）：2（水平）

的坡度上升，直到平均高高潮位以上 0 . 5

米為止。至於在極端荷載條件下，地下水

位沿 1：1的坡度上升至地面，是較為合理

的假設。

8 . 2 . 3 沉降問題

設計混凝土方塊牆時，必須評估它在

設計使用期內的總沉降量，以確保它的功

能不致受影響。在許多情況下，混凝土方

塊牆堆石地基的挖槽深度和寬度，都取決

於長期沉降的限制，而不是決定於地基以

下土層的抗圓弧滑動破壞之所需安全系

數。

67

9. DESIGN OF RUBBLE STRUCTURES

9.1 General

Information on the design of rubble structures isgiven in pages 7-202 to 7-249 of the Shore ProtectionManual (SPM) (CERC,1984). Further guidance isgiven in this Chapter on some aspects of the designof rubble structures, including comments on thechoice of design wave, stability formulae and thedetermination of crest level. It should be noted that,although this Chapter mainly covers rubble moundseawalls and breakwaters, many of the comments,particularly those covering toe protection and scour,apply equally to rubble foundations for gravitystructures such as concrete blockwork seawalls.

9.2 Design Wave

The designer should first assess the type of wavescritical for design of the structure. In general, forsheltered areas inside the harbour, short period locallygenerated storm waves will be predominant for theextreme case. In areas exposed to offshore waves,the effect of attack from long period swells has to bechecked. In some cases, the combined effect of thetwo types of waves has to be taken into account.

Notes on the selection of design wave for arubble structure are given in 7-2 to 7-4 and 7-203 ofthe SPM. It is recommended that the design waveheight for rubble seawalls and breakwaters, for use inHudson's formula referred to in Section 9.3, shouldnormally be taken as the average of the highest 10%of all waves, H10, which is approximately equal to1.27 times the significant wave height.

Hudson's formula does not include the effect ofwave period and is not recommended for use instructures subject to attacks from swells. In Van derMeer's Formulae, the significant wave height isadopted.

9 . 堆石結構的設計

9 . 1 概述

《 S h o r e P r o t e c t i o n M a n u a l》（下稱

《 S P M》） ( C E R C , 1 9 8 4 ) 第 7 - 2 0 2頁至

7 - 2 4 9頁，載述了設計堆石結構的資料，

本章為其中部分問題提供進一步指引，包

括設計波浪的選擇、穩定性公式和堤頂高

程的確定等。儘管本章主要論述的是堆石

海堤和防波堤，但其中多處，特別是關於

坡腳保護和 刷的部分，也同樣適用於混

凝土方塊海堤等重力式結構的堆石地

基。

9 . 2 設計波浪

設計海事結構時，設計人員應首先確

定波浪類型。一般來說，在極端情況下，

港內有掩護的水域，主要是受本地風暴引

起的短周期大浪影響；在開敞而受離岸波

浪影響的水域，則必須檢核長周期湧浪的

作用。在某些情況下，必須考慮兩種波浪

的共同作用。

《 S P M》第 7 - 2至 7 - 4頁和第 7 - 2 0 3

頁，載述了為堆石結構選擇設計波浪的方

法。利用第9 . 3節的H u d s o n公式設計堆石

海堤和防波堤時採用的設計波高，通常取

十分之一大波H 1 0 （即波群中以波高計最

大的 1 0﹪波浪的波高平均值），這約等於

有效波高的 1 . 2 7倍。

H u d s o n公式並沒有考慮波浪周期的

影響，因此，並不適宜用於設計受湧浪作

用的結構。V a n d e r M e e r公式則採用了

有效波高值。

68

The designer should consider the use of a higherdesign wave if one or more of the following factorsapply :-

(a) The structure is particularly important andmajor damage or failure would result in lossof life.

(b) The location is such that access formaintenance is exceptionally difficult and anymaintenance would be expensive.

(c) The design wave is from the easterly sector,which corresponds to the prevailing directionfor both normal and tropical cyclone winds.

(d) There is some doubt about the assessed waveheights, for example if the waves have beenforecast from wind records with a long orunlimited fetch.

(e) The structure is located in relatively shallowwater and regularly exposed to breakingwaves of similar magnitude to the designwave.

(f) The site is exposed to long period swell wavesof height similar to the design wave.

The use of a lower design wave height, such as thesignificant wave height, should only be considered if,say, three or more of the following factors apply:

(a) The structure is of minor importance andmajor damage or failure would not result inloss of life.

(b) Access for maintenance is easy and anymaintenance would be relatively inexpensive.

(c) The site is not exposed to long period swellwaves and the fetch is limited.

(d) Wave heights assessed from wind records aresupported by wave records.

如果出現下列任何一種情況，設計人

員便應考慮採用較高的設計波高：

( a ) 結構特別重要，嚴重損毀或破壞會

引致人命損失。

( b ) 維修異常困難，且維修費用昂貴。

(c) 設計波浪來自東面，無論是正常情

況或熱帶氣旋吹襲，這都是強風出

現頻率最高的風向。

( d ) 對設計波高存疑，例如，波浪是利

用風速記錄，再根據很長或無限長

度的風區推算出來的。

( e ) 結構位於伙較淺水域，並經常承受

與設計波高接近的破碎波作用。

( f ) 該位置受到接近設計波高的長周期

湧浪直接影響。

如果下列三項或以上情況出現，才可

考慮採用較低的設計波高，如有效波高：

( a ) 結構並不太重要，嚴重損壞也不會

導致人命損失。

( b ) 地點容易到達，維修方便，維修費

用也相對地較為便宜。

(c) 現場不受長周期湧浪的直接影響，

且風區長度有限。

( d ) 風速記錄推算的設計波高，有波浪

記錄加以驗證。

69

9.3 Stability

9.3.1 General

For the stability of rubble structures against waveattack, covering the design of armour, underlayers,bedding layers, core and toe protection, referencemay be made to pages 7-204 to 7-249 of the SPM.Comments on soil shear failure are given inSection 8.2 for rubble foundations of gravitystructures; these comments apply also to rubbleseawalls and breakwaters.

9.3.2 Design of Armour Units Using Hudson'sFormula

The design of armour units given by the SPM isbased on the use of Hudson's formula, see Eq. 7-116.Figures 21 and 22 in this Manual have been preparedusing this formula and the stability coefficients givenin Table 7-8 of the SPM to assist in the preliminarydesign of armour units consisting of rough angularquarrystone with random placement and layerthickness comprising two units. A unit weight for thearmour unit corresponding to a specific gravity of 2.6has been assumed, and curves are given for structureslopes of 1 on 1.5, 1 on 2 and 1 on 3 for breaking andnon-breaking wave conditions for structure trunkand structure head. The curves cover design waveheights up to about 6 m, with correspondingarmour weights up to about 10 t; this correspondsapproximately to the range of rock size normallyavailable locally, although rock in the upper part ofthis range will usually only be available in smallquantities.

For armour design, it is recommended that thespecific gravity of the rock, if obtained locally, shouldbe taken as 2.6. A figure higher than this value shouldnot be used for design without extensive testing, bothprior to construction, where a rock source has beenidentified, and during construction for qualitycontrol.

9 . 3 穩定性

9 . 3 . 1 概述

堆石結構在波浪作用下的穩定性設

計，包括護面、墊層、底層、堤心和坡腳，

可參閱《 S P M》第 7 - 2 0 4頁至 7 - 2 4 9頁。

第 8 . 2節關於重力式結構堆石基床的土壤

抗剪切破壞方面的論述，也適用於堆石海

堤和防波堤。

9 . 3 . 2 用H u d s o n公式設計護面塊體

《 S P M》載述了基於H u d s o n公式，設

計護面塊體方法，參閱方程 7 - 1 1 6。本

手冊圖 2 1和圖 2 2是根據該公式和《 S P M》

表 7 - 8列出的穩定系數製成的。這兩幅

圖有助護面塊體的初步設計，適用於粗糙

角形礦石，採取隨機散拋的方式放置的兩

層護面。製圖時假設護面塊體比重為

2 . 6，圖內曲線表示當坡面為 1 : 1 . 5、 1 : 2

和 1: 3時，在破碎波和非破碎作用下，防

波堤堤身和堤頭的所需塊體重量。附圖顯

示的設計波高最大約達 6米，塊體重量最

大約達 1 0公噸，這相當於本地常見的石料

重量範圍，雖然接近1 0公噸的石料通常只

有少量供應。

如果石料從本地供應，建議設計護面

塊體的比重值為2 . 6。除非在設計時能充

分測試擬用的石料，並在施工時有質量驗

證試驗，否則不應使用高於 2 . 6的比重

值。

70

9.3.3 Structure Head Conditions

It is recommended that, when using Hudson'sformula for armour design, and in particular thestability coefficients given in Table 7-8 of the SPM,the term "structure head" should be applied, not onlyto the ends of breakwaters, but also to all otherlocations/discontinuities, where normal "trunk"conditions no longer exist, including the following :

(a) where breakwaters or rubble seawalls havesharp changes in direction,

(b) at the ends of breakwaters or rubble seawallswhere there is a junction with a vertical-faceseawall, and

(c) where other types of construction/ structure,such as a vertical-face seawall with landingsteps or extensive culvert wing walls, havebeen incorporated into a length of breakwateror rubble seawall.

The length of structure to be considered ascorresponding to "head" conditions will bedependent on site conditions, crest level and armourslope, and must be decided by the designer in eachcase. As a guide, at any junction/discontinuity, headconditions should be taken for design purposes toextend at least 20 metres past the location where thenormal trunk section exists.

It is usual to cater for head conditions bymaintaining the same basic geometry of the structureused for trunk conditions and increasing the armoursize to suit the reduced stability coefficient. As analternative, if larger armour is not available, thearmour size can remain unchanged for headconditions and the armour slope adjusted instead.For smaller structures with significantjunctions/discontinuities where head conditionsapply, for simplicity it may be justified to use stabilityfactors corresponding to head conditions for the fullstructure length.

9 . 3 . 3 堤頭條件

當 使 用 H u d s o n 公 式 ， 特 別 是 使 用

《 S P M》表 7 - 8的穩定系數設計護面塊

體時，建議「堤頭」的範圍不要局限在防

波堤的末端，還包括不再具備「堤身」條

件的其他地方及間斷處，如以下幾種情

況：

( a ) 防波堤或堆石海堤定線方向有急劇

的改變，

( b ) 與直立式海堤相接的防波堤或堆石

海堤末端，及

(c) 有其他類型的結構加插在防坡堤或

堆石海堤堤身，如裝有登岸台階或

寬闊的通渠翼牆的直立式海堤。

結構屬於「堤頭」條件的長度，取決

於現場的狀況、堤頂高程和護面坡度，並

須由設計人員按個別情況確定。以下可作

為參考﹕在任何連接點和間斷處，從正常

堤身延伸至少 2 0米範圍內，於設計時須視

為屬於堤頭條件。

為滿足堤頭條件，設計通常會保持堤

身結構的基本外形，並加大護面塊體，以

適應較小的穩定系數。如果沒有較大的護

面塊體，則可保持其大小不變，而調整護

面的坡度。若一些小型結構具有大量的連

接點和間斷處，並符合堤頭條件，為簡便

起見，整個結構均可使用和堤頭條件相同

的穩定系數。

71

9.3.4 Model Testing

Where possible, armour design using Hudson'sformula and other aspects of rubble seawall andbreakwater design taken from the SPM should bechecked by model testing. For the majority of rubblestructures in Hong Kong, with maximum armoursize in the range of, say, 6 to 8 t, model testing will notnormally be practical based on economic andprogramming considerations. Where requiredmaximum rock armour sizes exceed the range givenabove, the use of precast concrete armour units willnormally be necessary; in this case model testing isconsidered essential and account must be taken ofthis when planning a project, with regard to the effecton costs and programming.

9.3.5 Design of Armour Units Using Van DerMeer's Formulae

The Van der Meer's Formulae have beenestablished based on the result of a series of modeltests using irregular waves. They are considered themost widely applicable of the prediction methodscurrently available and are based on the widest set ofmodel data.

These formulae take into account the waveperiod, number of waves, permeability of the coreand distinguish between breaking and non-breakingconditions. They are described as practical designformulae for rock armour, although experience intheir use is limited at present.

Details of the formulae are given in Van der Meer& Pilarczyk (1987).

When using Van der Meer's Formulae, the corepermeability factor, P, has to be assessed carefully.The values of P suggested range from 0.1 for arelatively impermeable core, up to 0.8 for a virtuallyhomogeneous rock structure. However, it should benoted that values are only assumed and have not yetbeen related to the actual core permeability.

9 . 3 . 4 模型試驗

利用 H u d s o n公式設計護面塊體以及

根據《 S P M》 設計堆石海堤和防波堤時，

應盡量透過模型試驗來驗證。香港的大部

分堆石結構，最大護面塊體為6至 8公噸，

基於成本和進度規劃的考慮，模型試驗未

必可行。當所需的最大護面塊石超出了上

述範圍時，一般會用預製混凝土護面塊體

代替。在這種情況下，必須進行模型試

驗，同時在規劃工程項目時，也應該考慮

到模型試驗對工程造價及進度的影響。

9 . 3 . 5 用V a n d e r M e e r公式設計護面塊體

V a n d e r M e e r公式是根據一系列不規

則波模型試驗的結果而建立的。它是目前

應用最廣泛的方法，並且是根據最多的模

型試驗數據得出的。

這套公式考慮了波浪周期、波數、堤

心滲水性以及破碎波和非破碎波之間的

區別。儘管目前應用這套公式的經驗還很

有限，但它已被接受為設計護面塊石的適

當公式。

V a n d e r M e e r & P i l a r c z y k ( 1 9 8 7 ) 有

這套公式的詳細介紹。

使用V a n d e r M e e r公式時，必須慎重

確定堤心的滲水系數 P。P值的建議取值

範圍是 0 . 1至 0 . 8，堤心相對地不透水時應

取 0 . 1，而均勻的塊石結構則取 0 . 8。然

而，應注意P只是假設值，其與實際的堤

心滲水性的關係尚未確定。一般防波堤的

滲水系數取 0 . 3，海堤或護坡則取 0 . 1至

72

Permeability coefficients of 0.3 for normalbreakwaters and 0.1 to 0.2 for normal seawalls orrevetments are suggested. Ultimately the choice of Pmust depend on the designer's judgement, and it isstrongly recommended that the permeability beunderestimated rather than over-estimated, if indoubt. Sensitivity of the final calculated rock weightto the assumed value of P should always be checked.

Unless data available allow more detailedassessment to be made, it has been suggested that thefollowing values be used :-

N = 3000 to 5000

S = 1 to 3 (roughly equivalent to 5% damage)

It should be noted that experience in theapplication of these formulae is limited. Their useshould not be extended beyond the experimentallimits. Except for relatively sheltered areas and forsmall or unimportant structures, physical model testsare strongly recommended to verify the design.

9.4 Crest Level

Notes on crest elevation and width are given inpages 7-229 to 7-233 of the SPM , and wave runup iscovered in pages 7-16 to 7-43. For the majority ofrubble structures covered by this Manual, whereminor overtopping during the design event can betolerated, the design wave for the assessment ofrunup can be taken to be equal to the significant waveheight applicable at the structure. The crest level ofthe rubble structure will be the extreme water levelplus the runup corresponding to this design wave,plus an allowance for structure settlement during thedesign life, plus a nominal allowance for freeboardof, say, 0.2 to 0.3 metre.

An indication of the extent of overtopping to beexpected, if the design wave for assessing runup istaken to be the significant wave height, can beobtained from Figure 7-23 of the SPM. The runupheight exceeded by 10%, 5%, 2% and 1% of the

0 . 2。P值的選擇最終須由設計人員判斷。

要特別強調的是，當沒有十分把握時，寧

可低估也不要過高估計P值。設計時應校

核最終計算出的塊石重量對 P值的敏感

度。

如果沒有充分的數據來做更準確的估

算，建議採用下列數值：

N = 3 0 0 0至 5 0 0 0

S = 1至 3（約等於 5﹪的損壞）

由於應用這公式的經驗尚屬有限，其

使用範圍不應超出原來模型試驗參數的

限制。除相對地隱蔽的水域，及小型或次

要的結構外，建議其他設計須通過物理模

型試驗來驗證。

9 . 4 堤頂高程

《 S P M》第 7 - 2 2 9頁至 7 - 2 3 3頁載述

了堤頂高程和寬度的資料；第 7 - 1 6頁至

7 - 4 3頁載述了波浪上衝的高度。本手冊

內涉及的大部分堆石結構，在設計條件下

可容許有少量的越堤浪，設計時可用作用

在結構的有效波高來評估上衝高度。堆石

防波堤的堤頂高程應為最高水位、上衝高

度及結構在設計使用期內的預留沉降量

的和，再加上約 0 . 2至 0 . 3米額定富裕高

度。

如果以有效波高為設計波浪來估算上

衝高度，則可從《 S P M》圖 7 - 2 3估計波

浪越堤的程度。被 1 0﹪、 5﹪、2﹪和 1﹪

波浪超越的上衝高度，約比有效波高的上

衝高度高 8﹪、 2 3﹪、3 9﹪和 5 2﹪。波浪

73

waves is approximately 8%, 23%, 39% and 52%respectively greater than the runup for the significantwave, and the runup from approximately 13% of thewaves will exceed that for the significant wave.

Notes on concrete caps, including wave walls, forrubble structures is given in pages 7-235 and 7-236 ofthe SPM. For both breakwaters and rubble seawalls itis recommended that concrete caps/wave wallsshould be avoided where possible. The need for awave wall can often be avoided simply by increasingthe crest level of the rubble structure. If a wave wallis considered essential, for example for a rubbleseawall to reduce minor overtopping to theminimum, the wave wall should be founded on anunderlayer or the core, not the primary armour layer,and should be set back from the primary armourunits. Any wave wall itself should consist ofsubstantial concrete blocks, preferably keyed andunreinforced, and should be capable of taking somedifferential settlement; a rigid wave wall designfounded on a flexible rubble structure should beavoided.

約有 1 3﹪會超越有效波高的上衝高度。

《 S P M》第 7 - 2 3 5頁和 7 - 2 3 6頁，載

述了堆石防波堤的混凝土護頂（包括防波

牆）。在可能情況下，應避免在防波堤和

堆石海堤使用混凝土護頂和防波牆；可通

過提高結構的頂高程來代替防波牆。如必

須使用防波牆（例如利用防波牆來將越堤

浪減至最少），則它應建在墊層或堤心

上，而不是在護面層上，並應放在護面塊

體之後。防波牆應由大塊的混凝土塊組成

（最好用鍵接和無配筋方塊），並能承受

不均勻的沉降；應該避免將剛性防波牆座

落在柔性的堆石結構上。

74

75

10. DESIGN OF RECLAMATIONS

10.1 General

This Chapter gives brief comments and guidanceon the design of reclamations, covering such aspects asextent and layout, reclamation level and methods, fillmaterials, and miscellaneous related matters includingpiling through reclamations, and culvert foundations.

The design of a reclamation should be carried outwith the aim of fulfilling the requirements of theplanned use and programme for development,particularly with regard to time/settlementcharacteristics of the reclamation and foundationmaterials. The timing of the future development is ofparticular importance, together with the location offuture roads, drains, buildings and areas of open space.It should be noted that sometimes it may be necessaryto design reclamations for the main initial purpose ofspoil disposal; in such circumstances, future land useand development is likely to be known only in generalterms at the time of reclamation design. It is relativelycommon for planned use and development ofreclamations to change with time, due to changingneeds, and account should be taken of this wherepossible by designing reclamations for flexibility of use.

Site investigations prior to the design ofreclamations are particularly important in order to beable to arrive at the most appropriate design, asreclamation projects are usually extensive, carryingmajor financial implications if problems developduring or after the construction stage. In addition tothe normal investigations required for marinestructures, the investigations may need to coverpotential sources of fill materials. In particular, insituand laboratory testing of soil samples within theproposed reclamation area should be carried out withthe aim of determining settlement characteristics ofunderlying marine and alluvial soils.

1 0 . 填海工程的設計

1 0 . 1 概述

本章有設計填海工程的簡要論述和指

引，涉及範圍包括：平面佈置、填築高程、

回填方法、回填材料，以及有關填海區打

樁和暗渠地基等問題。

填海工程的設計，應滿足既定規劃用

途和發展時間表的要求，特別應要考慮到

回填材料和地基材料會隨時間而沉降的

特性。計劃發展的時間，以及道路、排水

系統、建築物及遊憩用地的佈局都十分重

要。應該注意的是，有時填海工程的主要

目的，是盡快提供廢料棄置地方；在這種

情況下，很可能在設計時仍對未來土地的

使用和發展所知有限。由於填海區的使用

和發展，常因不同需要而變化，在設計

時，應充分考慮到上述因素，讓土地能靈

活使用。

為做到最適當的設計，填海工程設計

前的現場勘測極為重要，因為填海工程項

目的規模通常很大，如果在建設階段或建

成後出現誤差，便會造成較大的經濟損

失。除海事結構所需的一般勘測外，還須

研究可能的填料來源，特別是應對擬定的

填海區內的土質進行現場試驗或實驗室

試驗，以便確定海床下海相和沉積土壤的

沉降特性。

76

10.2 Extent and Layout

The extent of a reclamation will be governed largelyby the shape of the existing shoreline, where an existingbay or indentation is to be reclaimed, and by strategicplanning for more extensive reclamations, where majorchanges to the land/sea boundary result. The majorlimitations on the extent of reclamations will be waterdepth, and the need to maintain fairways, mooringsand other marine traffic channels and clearances to theapproval of the Director of Marine.

For all major reclamations, and for minorreclamations where there is a significant change in theshape of the land/sea boundary, it will be necessary tocarry out detailed investigations, including physical andmathematical modelling, to ensure that the changes incurrents, waves and storm surge characteristicsexpected to be caused by the reclamation have nounacceptable effects with respect to :

(a) navigation of large and small vessels,

(b) tidal flushing and water quality,

(c) siltation and seabed scour,

(d) the operation of piers, wharves andcargo-handling areas, and

(e) flooding due to tides combined withstorm surge.

It must be recognised that the effects of areclamation on water flow in general, and currents,waves and storm surge characteristics in particular, cancover a far more extensive area than the areaimmediately adjacent to the reclamation itself, and thedetailed investigations referred to above should takethis into account.

The layout of a reclamation will largely be governedby town planning considerations. However, marine-frontage related uses on the planned reclamation, suchas piers, wharves, cargo-handling areas, seawater

1 0 . 2 範圍和佈置

在現有海灣或凹入處填海，其範圍主

要取決於現有海岸曲線；若按策略性規劃

進行大規模填海，則海岸線將有很大變

化。填海範圍主要的制約因素有：水深、

主航道、停泊區及其他海上運輸航道和間

距，應取得海事處的批准。

所有大型填海工程，以及使海岸線產

生重要變化的小型填海工程，均須事先進

行詳細研究，包括物理和數學模型試驗，

以確保填海工程引起的水流、波浪和風暴

潮增水等特性的變化，不致在以下各方面

產生不能接受的影響：

( a ) 大小船舶的航行，

( b ) 潮汐 洗作用和水質，

(c) 淤積和海床 刷，

( d ) 碼頭和貨物起卸區的作業，及

( e ) 潮汐和風暴潮增水共同作用引起的

泛濫。

由於填海工程對於水流，特別是對流

速、波浪和風暴潮增水的影響，所及範圍

可能覆蓋遠離填海區的水域。因此，這些

考慮亦應包括在上述詳細研究內。

填海區的平面佈置很大程度取決於城

巿規劃。但是，填海區海傍土地的使用，

如碼頭、貨物起卸區、海水進水口以及雨

水和污水排放口等，都應及早確定，以便

77

intakes, stormwater and sewerage outfalls, need to beidentified at an early stage. The proposed locations ofsuch structures, areas and facilities will need to beknown, at least in general terms, at the time of thedetailed investigations referred to above.

The layout of a reclamation, with regard to thelocations of roads, bridges, buildings, stormwaterculverts and major sewers, is important whenconsidering the settlement characteristics of the fillmaterial to be used in different areas of the reclamationand the proposed reclamation method. However, aspointed out in Section 10.1, reclamations should bedesigned for full flexibility of land use where possible.

10.3 Reclamation Level

Before deciding on the finished level for areclamation, the following aspects should beconsidered :

(a) the availability and cost of fill,

(b) the urgency of the land development,

(c) existing ground, road and drain levelsfor adjacent developments,

(d) post-construction settlement of the filland underlying marine and alluvialsoils,

(e) the type of seawall and the extent ofwave overtopping expected,

(f) normal and extreme still water levelsdue to tides combined with stormsurge,

(g) land use of sea frontage, and

(h) possible long term increase in meansea level.

進行上述詳細研究。

當考慮在填海區內的各個區域，採用

具有不同沉降特性的填料，及不同的回填

方法時，區內的道路、橋樑、建築物、雨

水渠和主要污水渠的位置是十分重要的

因素。但是，如第1 0 . 1節所述，設計填海

工程時應盡可能顧及土地靈活使用的要

求。

1 0 . 3 填築高程

決定填海的最終高程之前，應考慮以

下幾方面：

( a ) 填料的供應和價格，

( b ) 土地開發的迫切性，

(c) 現有相鄰土地、道路和排水溝渠的

高程，

( d ) 建成後填料、下臥海相和 積土壤

的沉降，

( e ) 海堤的類型和預計越堤浪的量，

( f ) 正常靜水位以及潮汐和風暴潮增水

共同作用下的極端水位，

( g ) 海傍土地的用途，及

( h ) 長期的平均海水水位上升。

78

It is relatively easy in most cases to ensure that aseawall cope level and reclamation level is higher thanextreme still water level corresponding to a reasonablereturn period of, say, 100 years, or even 200 yearswhere flooding would cause substantial damage tolives and property. However, it is generally notpossible or practical to design a seawall, even with theaddition of a wave wall, to effectively preventovertopping from waves during extreme events. Acertain degree of overtopping, particularly withvertical-face seawalls, is always to be expected at timesof extreme water level from the higher waves in thespectrum, and the drainage immediately behind theseawall should be designed to cater for this if majorflooding is to be avoided. Wave walls are likely to beof only limited use in controlling or preventingextensive overtopping unless careful detailing is carriedout at discontinuities such as piers, wharves,pumphouses and landing steps.

It has been common practice in the past to use anominal figure of +4.0 mCD for reclamation andseawall cope levels within the general harbour area.This figure should not be used for future reclamationswithout detailed consideration being given to thepoints listed above. All reclamations should beconsidered on an individual basis, and theconsequences of adopted reclamation level fullyinvestigated, before determining the most appropriatelevel in each case.

10.4 Reclamation Method

10.4.1 General

The design of a reclamation with regard tosettlement is dependent on the method used to formthe reclamation. Three main reclamation methodshave been used in the past under local conditions, eachone different in terms of reduction or control ofsettlement. These are : full removal of marine deposits,displacement of marine deposits, and controlled fillplacement, combined with the use of vertical drains asnecessary. Each of these methods is described brieflybelow, with comments on particular aspects,advantages and disadvantages in each case. Permanent

一般情況下，要確保海堤堤頂和填海

區的高程，高於會造成生命財產重大損失

的極端靜水位，例如1 0 0年甚至 2 0 0年一

遇的水位，並不困難。然而，要設計一個

能有效防止在極端情況下出現越堤浪的

海堤，縱是加上防波牆，都是不可能或不

切實際的。水位到達極端情況時，波譜中

較大的波浪總會產生一定程度的越頂現

象，直立式海堤會令情況更加嚴重。海堤

後方應設置排水渠，以防止海水大量灌

入，引起泛濫。除非在間斷處，如碼頭、

泵房和登岸台階等地方，小心設計各項細

節，否則防波牆在控制或防止大量越堤浪

方面的作用十分有限。

以往，在海港內的填海區和海堤堤頂

高程，都普遍採用海圖基準面上 4 . 0米。

除非已仔細衡量上述各項因素，否則將來

的填海工程不應再採用該高程。所有填海

工程均應根據個別具體情況考慮，在確定

最合適的填築高程之前，須詳細研究可能

出現的後果。

1 0 . 4 回填方法

1 0 . 4 . 1 概述

填海工程有關沉降的設計，取決於回

填方法。在香港回填方法主要有三種，它

們在減少或控制沉降方面的特性各不相

同。該三種方法是：海相沉積土清除法、

海相沉積土排移法和控制填放法，而按情

況可與豎向排水相結合。下文將分別簡要

介紹以上各方法，並論述其特點、優點和

不足之處。永久性土地用途，是決定採用

那種回填方法前須考慮的主要因素。

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land usage is a major factor which should beconsidered before deciding which method ofreclamation is to be adopted.

10.4.2 Marine Deposit Removal

Settlement can be controlled effectively byremoving all marine deposits by dredging. Normally,dredging will stop when alluvium or weathered rockhas been reached, as determined by detailed groundinvestigation. This can be expensive where thickmarine deposits exists, and disposal of marine mud,particularly contaminated mud, may be severelyproblematic. However, the basic method is relativelysimple, both dredging and filling operations can becarried out with minimal restrictions, and a relativelyshort overall construction programme can be achievedcombined with an economical cost, even when largequantities of mud and fill are involved.

The removal of upper marine deposits only, withthe lower, stiffer or stronger deposits remaining inplace, has the advantage of reduction in dredging andfill quantities, and may be adequate in certaincircumstances. Better control is required than for fullmarine deposit removal for the final trimming indredging and for initial fill placement, to avoid futuredifferential settlements, compared with full marinedeposit removal. The remaining relatively thin layer ofmarine deposits will consolidate relatively quickly undervertical drainage through the fill during the fillingoperation, with the major part of the total settlementprobably being completed during the reclamationformation period. The extent of marine deposits to beleft should be subject to investigation and detaileddesign, and should depend on the magnitude ofdifferential settlement which can be tolerated in theparticular situation. Post-construction problems mayarise if undetected deep pockets of mud are left inplace.

10.4.3 Marine Deposit Displacement

This method involves direct tipping of fill, possibly

1 0 . 4 . 2 海相沉積土清除法

挖去所有海相沉積土，可以有效地控

制填海區的沉降。通常，挖掘到達 積層

或風化岩時便停止，但要通過詳細的地質

研究來確定。如海相沉積土較厚，該方法

造價會很高，而且棄置海底淤泥也異常困

難。如果淤泥已受污染，問題會更嚴重。

但是，相對來說，此法較為簡單，挖泥和

回填作業都很少限制，即使挖填工程量很

大，所需施工期也會較短，而且費用較

低。

此外，還可以僅將上層海相沉積土清

除，而保留下層較硬或較堅實的沉積土，

其優點是可以減少挖填量，這在某些情況

下是較好的方法。挖泥後的整理和最初的

填料投放，其質量控制比清除全部沉積土

要求更高，以避免將來的不均勻沉降。在

回填時，採用豎向排水管排水，可以加快

剩下的海相沉積土層的固結速度，使大部

分的沉降在回填期間便完成。至於可保留

的海相沉積土厚度，應取決於在該具體情

況下可容許的不均勻沉降，針對這問題，

應進行詳細勘測和設計。如果在挖泥局部

地方留下深厚的淤泥未被發覺，建成後便

可能會出現問題。

1 0 . 4 . 3 海相沉積土排移法

此法是將可能包括公眾卸泥物料的填

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including public dump material (see Section 10.5.2),from trucks onto the surface of the marine deposits.Initial filling is often carried out along the lines of futureroads and drainage reserves; as filling progresses, thesofter upper marine deposits are displaced to the sidesand in front of the reclamation bund or line. Thedisplaced marine deposits or mud waves can often becontrolled by forming the initial reclamation in bundson grids. Where displaced marine deposits are notsufficiently dry and stable to be eventually covered byfill, they are removed by land based plant, transportedto a barging point by truck and disposed of at a marinedumping site. Such removal is relatively expensive on aunit cost basis because of the multiple handling, but inrelation to the overall project cost is usually not ofmajor consequence; the total quantity of marinedeposits required to be removed is usually small inrelation to the total quantity covered and the total fillquantity.

Where initial filling is carried out on a wide frontrather than in bunds, it is often possible for excessdisplaced marine deposits in front of the reclamationline to be removed by grab dredger and bottom-dump barges, provided adequate access and waterdepths can be maintained. The unit cost for suchremoval will be significantly lower than for removal byland based plant, but the total quantity required to beremoved will be larger, as less material will be coveredby the fill.

The reclamation method referred to above gives avery low initial cost for the reclamation, particularlywhere public dump material is used for filling.Reclamation by marine deposit displacement can bethe most appropriate and economical method wherepublic dump material is available, low initial cost isimportant and permanent development of the land soformed is not urgently required. However, where thickmarine deposits occur, the method can result in longterm settlement problems due to consolidation of thetrapped marine deposits under the fill. Where initialreclamation is carried out by end-tipping on a widefront or in bunds, it is never possible to ensure that allmarine deposits are displaced. Any remaining mudtrapped under the fill will be of unknown and variable

料，直接由運泥車傾倒在海相沉積土的表

面（見第 1 0 . 5 . 2節）。最初的回填通常沿

未來的道路和排水專用範圍進行。隨

回填工程的進展，較軟的上層海相沉積

土，被排移到回填料的兩側和回填區的前

緣。被排移的海相沉積土造成的淤泥流動

現象，可通過事先填築縱橫交錯的堤壆來

控制。如果被排移的海相沉積土不夠乾實

或穩定以接受填料覆蓋，便需用陸上的設

備挖掘，用運泥車運至躉船載運站，再由

躉船拋置於海上卸泥區。因要重覆處理物

料，這樣的綜合處理方法，以每單位量計

費用可能會較高，但因為須要清除的泥土

數量一般要比被覆蓋的淤泥量和總填土

量要小得多，所以，其所需費用在整個工

程項目中並不會佔太大比重。

若回填是從開闊的前緣開始而不是利

用堤壆，並且能夠維持適當的航道和水

深，便可用抓斗式挖泥船和開底運泥船，

清除回填線前方被排移的過剩海底淤

泥。用此種方法清除淤泥的造價以每單位

量計大大低於使用陸上設備的造價，但是

需要清除的總量較大，被回填料覆蓋的淤

泥也較少。

上述回填方法初期費用很低，特別是

利用公眾卸泥物料作為填料，會更為便

宜。在那些有公眾卸泥物料可用、初期投

資預算較低，以及不急需土地進行永久性

發展的地方，用海相沉積土排移法回填，

可能是最合適、最經濟的。但是，在海底

淤泥很厚的地方，由於填料下面殘留淤泥

的固結，此種方法會導致長期的沉降問

題。如果初期回填是用運泥車在開闊的前

緣或填築的堤壆間傾倒物料，便無法保證

所有淤泥都已被排移。由於殘留在回填料

下面的淤泥厚度不能確定，也不均勻，所

以會引起不均勻沉降問題，其中包括不同

沉降值和不同固結期的影響。若最初被排

移的淤泥被分隔在堤壆內，再被填料部分

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thickness, and can give rise to differential settlementproblems, related notonly to different settlementmagnitudes but also to different periods forconsolidation to take place. Where initially displacedmarine deposits are isolated within bunds and laterpartially or completely covered by fill, the settlementproblems are likely to be even greater, as these marinedeposits will be from the upper layers and remoulded,and therefore of lower strength, and the overallthickness of marine deposits within the bunds will begreater than the original thickness. Differentialsettlements between areas formed as bunds and areaswithin bunds will usually be significant.

10.4.4 Controlled Thin Layer Fill Placement

This method leaves the existing marine depositsundisturbed, and involves the controlled placement ofrelatively thin layers of fill to avoid shear failure in theunderlying soils and ; 'mud waves', usually usingbottom-dump barges, hydraulic filling or grab. Theinitial capping or blanket layer is particularly importantand should consist of free-draining granular material toensure satisfactory vertical drainage from the marinedeposits. Initial thicknesses of one to two metres areusually required, with subsequent layer thicknessesincreased as appropriate. Layers must be staggered,with control being exercised to ensure a sufficientleading edge for the underlayer in relation to the layerbeing formed. When a total thickness of about 5 m offill has been placed, the degree of control may bereduced, and it is often possible to complete thereclamation using end-tipping by truck, again in layers ifnecessary.

Where the thickness of marine deposits is too greatto ensure that settlements will have been substantiallycompleted before final development of thereclamation is required, special measures to increase therate of consolidation will be required. Such measuresinclude the use of vertical drains, surcharging, or acombination of these measures.

Vertical drains are drainage conduits inserted intocompressible soils of low permeability (typically, the

或完全覆蓋，沉降問題會更加嚴重，因為

這些淤泥來自沉積土上層，又經過重塑，

因此其強度較低，而且此處的淤泥層厚度

比原來的更大。在這種情況下，堤壆本身

與堤壆內地區之間的不均勻沉降通常會

很嚴重。

1 0 . 4 . 4 控制薄層填放法

這種方法可使海底淤泥不受擾動，並

通過有控制地投放薄層回填材料，避免下

層土壤的剪切破壞和淤泥流動。回填時通

常採用開底運泥船、水力填築或抓斗填

築。最初的覆蓋層非常重要，應由透水性

良好的粒狀材料組成，以確保海底淤泥能

通暢地進行豎向排水。最初覆蓋層厚度可

定為 1至 2米，以後逐漸增加。各層必須交

錯回填，同時應加以控制以確保下填層和

新填層兩者的前緣之間有一個適當的距

離。當回填的總厚度達 5米時，控制的標

準便可降低一些。這時，一般可用運泥車

傾倒至完成回填為止，但如有需要，仍應

分層進行。

如果海底淤泥太厚，而預計沉降不會

在填海區進行永久性發展前停止，便須採

用特殊措施加快固結速度，包括使用豎向

排水管、加載或兩者並用。

豎向排水管是插入具有低透水性的可

壓縮土壤（如海底淤泥）中的排水通道，

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marine deposits) to enable the pore water in the soilmatrix to drain horizontally to the conduits, and thenvertically through the conduits to the free draining layerprovided on top of the deposits, and to morepermeable underlying soils. The rate of consolidationof the marine deposits will depend on the drain size,drain spacing and the properties of the deposits.Prefabricated paper or plastic band drains are the mostcommonly used in local conditions because of theirresistance to shearing (Premchitt & To, 1991). Atriangular spacing in the range of 1.5 to 3.0 m is normal,with primary consolidation, (which can be in the orderof 20 to 30% of the thickness of the marine deposits),being completed within one to two years for typicalsites with 5 to 10 m thickness of marine deposits,compared with 10 to 20 years if no vertical drains areused. To avoid the need for preboring through thereclamation fill, the band drains are commonly installedover water using special plant, through the blanket layerof free draining granular material, prior to the fill beingplaced. For additional information, reference may bemade to the various published papers related to the testembankment at Chek Lap Kok.

The rate of consolidation of marine deposits can beincreased by the application of a temporary surchargeload. Surcharge loads are usually applied immediatelyon completion of a part of the reclamation to designlevel, using fill. By careful planning, after completion ofconsolidation, the surplus surcharge fill can be usedelsewhere in the reclamation, so reducing doublehandling costs to the minimum. When combined withthe use of vertical drains, surcharging can be a veryeffective method of increasing the rate of consolidationof thick marine deposits.

Reclamation using controlled thin layer fillplacement, combined with the use of vertical drains,surcharging or both where appropriate, can be themost suitable and economical method for largeprojects on thick marine deposits, where fill is costly,disposal of dredged mud is problematic, anddevelopment of the land is required within a year or soof the filling completion date. However, it should benoted that the techniques involved with thin layer fill

使土壤中的孔隙水橫向地流入排水管，然

後通過豎向排水管，排到淤泥上面透水性

優良的回填層及透水性較好的下臥土

層。海底淤泥的固結速率，取決於排水管

道的大小、間距和淤泥的性質。預製的紙

或塑料排水板，具有良好的抗剪性能

( P r e m c h i t t & T o , 1 9 9 1 )，因而在本地廣

泛使用。通常排水管採用間距為1 . 5至 3 . 0

米的三角形佈置，用於海底淤泥厚度為 5

至 1 0米的典型地點，初步固結（達海底淤

泥厚度的2 0至 3 0﹪左右）可在1至 2年內

完成。若不使用豎向排水管，便需1 0至 2 0

年。為避免在回填層上鑽孔，安放排水板

時，通常會在回填材料投放前，利用在水

面運作的專用設備，將排水板穿過透水性

好的粒狀材料層。進一步的資料，可參考

已發表的有關赤 角試驗性圍堤工程的

論文。

堆加臨時荷載的方法可加速海底淤泥

的固結。通常當其中一部分的回填達到設

計高程後，便立即用填料施加荷載。通過

周密計劃，在固結完成後，餘下的加載填

料可用於填海區的其他地方，這樣可減少

重覆處理的費用。附加荷載和豎向排水管

結合使用，是加快較厚的海底淤泥固結的

有效方法。

對於在較厚的海底淤泥上進行大型的

工程項目來說，如果回填材料較貴，挖出

的淤泥難以處理，或回填完成後大約一年

就要進行土地發展，那麼，在採用控制薄

層填放法的同時，結合豎向排水法、加載

法或兩者兼用，可能是最合適、最經濟的

方法。應該注意的是，薄層回填和安放豎

向排水管所涉及的技術較為複雜，需要有

嚴格監管和有經驗的承建商。應用控制薄

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placement and vertical drain installation are relativelysophisticated compared with other reclamationmethods, and require tight control and experiencedcontractors. With controlled thin layer fill placement,close monitoring on site is necessary andinstrumentation, including piezometers, inclinometers,sub-surface and surface settlement measurementsystems, and monitoring will be needed.

10.5 MISCELLANEOUS

10.5.1 General

Comments on particular aspects of reclamationdesign related to piling and culvert foundations aregiven below.

10.5.2 Piling

Obstructions to piling installed at reclamation sitescan cause serious problems, with cost overruns andprogramme delays. The largest rock or boulder sizeencountered when driving piles must be breakable byimpact or be capable of displacement. For the lattercase there must be sufficient voids in the fill to copewith the pile volume and allow the displacement.Experience has shown that 250 mm is theapproximate upper limit in rock or boulder size withinthe fill to ensure no major problems with theinstallation of the types of piles normally used,including driven concrete, steel H-section and steeltubular piles, and bored piles.

For bored piles, permanent steel liners are usuallynecessary to avoid necking, particularly in crushed rockfill or where pockets of unconsolidated marinedeposits are suspected, as would be the case if marinedeposit displacement had been used for thereclamation method. Special shoes or reinforcedsections or points are normally required for drivenpiles, particularly in public dump material or crushedrock fill.

層填放法時，必須進行嚴密的現場監測，

和使用包括水壓計、傾斜儀、地面和地底

的沉降測量系統等檢測儀器。

1 0 . 5 其他

1 0 . 5 . 1 概述

下文專門論述與打樁和暗渠地基有關

的回填設計。

1 0 . 5 . 2 打樁

在填海區內打樁遇到障礙時會導致嚴

重問題，如費用超支和工期延誤等。打樁

碰到大塊岩石或巨礫，必須將其擊碎或移

開。在後一種情況，回填材料必需有足夠

的孔隙，以容納樁柱的體積，並讓大石塊

移開。據以往經驗，如要保證各種常用的

樁在裝置時不會出現大問題，回填材料中

石塊和巨礫尺寸的上限約為 2 5 0毫米。常

用的樁包括混凝土樁，H型鋼樁，鋼管樁

和鑽孔灌注樁。

在填海區的鑽孔灌注樁，通常要使用

永久性鋼套管以避免頸縮，在碎石回填區

或懷疑有尚未固結海底淤泥的地區，更應

注意。在使用海底沉積土排移法回填的填

海區，就要採用這種方法。若是使用打入

樁，通常須裝上特別的樁靴、加勁裝置或

尖咀；在使用公眾卸泥物料或碎石作填料

的地區，更應注意。

所有設置在填海區內的樁 ，在設計

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For all piles installed in reclamations, the possibleeffects of negative skin friction on the pile designshould be assessed. The magnitude of the negative skinfriction on any site will depend on the pilecharacteristics, fill characteristics, pile movement andthe time since the reclamation was completed.

10.5.3 Culvert Foundations

Existing stormwater outfalls will need to betemporarily diverted away from the line of the futureculvert extensions while reclamation is being carriedout. The type of foundation to be used for a culvertextension across the new reclamation will depend onthe method of reclamation used and the degree ofconsolidation of any remaining marine deposits.

Where the marine deposits have been fully removedor where consolidation of any remaining deposits haseffectively been completed before culvert constructioncommences, a normal foundation for the culvert,consisting of a nominal crushed rock or rubble layer,will usually be acceptable. Where marine depositdisplacement has been used as the reclamation method,with a bund being formed along the line of the futureculvert, a normal foundation as described above canusually be used following surcharging. Suitablesurcharging would be carried out with surplus fill overa strip two to three times the width of the culvert andabout four metres high for a period of three to sixmonths until settlement has stabilised.

Where consolidation of any remaining marinedeposits has not effectively been completed or wherevariable thicknesses of underlying marine deposits aresuspected, surcharging as outlined above can be ofassistance in controlling settlement problems, but it isrecommended that special measures are taken to allowfor some differential settlement at the culvert joints.The use of piled foundations may be considered wheredifferential settlement problems are expected to beparticularly severe, but such a solution will be relativelyexpensive on an initial cost basis, and can result in otherforms of settlement problems, as outlined below.

時，都應考慮樁身表面負摩擦力的影響。

表面負摩擦力的大小，取決於樁的性質、

填料的特性、樁的移動和回填完成的時間

等因素。

1 0 . 5 . 3 暗渠地基

在回填過程中，現有雨水排放口須從

擬建的暗渠延伸線上暫時改道。至於貫穿

新填海區內的暗渠地基類型，取決於回填

方法和殘留海底淤泥的固結程度。

如果在暗渠開始施工之前已清除了淤

泥，或所有留下的淤泥已完成固結，暗渠

的地基可以採用較薄的毛石或碎石層。如

果使用了海相沉積土排移法，並在沿擬建

暗渠定線上築了堤壆，通常可用以上提到

的地基設計，並經加載處理。加載範圍覆

蓋暗渠寬度的兩至三倍、厚約 4米，經三

至六個月時間，直至沉降穩定為止。

在殘留的海底淤泥尚未有效固結，或

懷疑有不同厚度的淤泥之處，加載方法有

助於控制沉降問題，但建議在暗渠構件的

連接處，採用特殊方法處理不均勻沉降。

在預計不均勻沉降特別嚴重之處，可考慮

採用樁基，但此法造價較高，並且可能導

致下述的沉降問題。

85

Normally culvert outfalls are formed in concreteblock seawalls using special concrete outfall blocks.Such seawalls usually have rubble foundations and willexperience some settlement with time, causingdifferential movement to develop at the junction with apiled culvert. In addition, differential settlement willalso develop with time along each side of a piledculvert, as the adjacent reclamation material continuesto settle over the underlying consolidating marinedeposits.

通常，暗渠排水口是用特製的混凝土

構件，安置在混凝土方塊海堤內，這種海

堤通常採用堆石地基，會有持續沉降現

象，因而導致排水口與樁基暗渠的連接處

出現不均勻位移。此外，由於下臥層海底

淤泥的固結，會導致回填材料持續沉降，

因而樁基暗渠與兩側的不均勻沉降還會

不斷增加。

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11. CONSTRUCTION MATERIALS

11.1 General

This Chapter gives comments and guidance onparticular matters considered of importance for thedesign of marine structures concerning materialselection, use and specification. The materials coveredare armour rock, filling, concrete, steel, timber andrubber. For general information on these materials andany other materials used in marine structures, referenceshould be made to the General Specification for CivilEngineering Works (GS) (Hong Kong Government,1992a). Comments on piles and protective measures inrelation to material selection and use are also given inthis Chapter.

11.2 Armour Rock

It is recommended in Section 9.3.2 that a specificgravity of 2.6 should normally be used for armourdesign; this figure corresponds with the minimumrequirement for armour rock given in Section 21 of theGS. The requirements given in the GS for armourrock are in agreement with those given in Clause 57.2of BS 6349:Part 1 (BSI, 1984a), although in this clauseit is noted that lower standards of quality may beacceptable for stone to be used in layers other than theprimary armouring. Clause 57.1 of BS 6349:Part 1recommends that individual stones should beprismoidal in shape, with the maximum dimensiongenerally not exceeding twice the minimum dimension,and never exceeding three times the minimumdimension. As stated in Section 9.3.4, the normalmaximum armour size available locally in reasonablequantities is in the range 6 to 8 t, although sizes up toabout 10 t may be available in small quantities.

11.3 Fill

11.3.1 General

When placing fill under water, the material and

1 1 . 施工材料

1 1 . 1 概述

本章重點論述設計海事結構時，護面

塊石、回填料、混凝土、鋼、木材和橡膠

等材料的選擇、應用和規格，同時也提供

有關的指引。至於其他物料的一般資料，

可 以 參 考 《 G e n e r a l S p e c i f i c a t i o n f o r

C i v i l E n g i n e e r i n g W o r k s》 （下稱《G S》）

( H o n g K o n g G o v e r n m e n t , 1 9 9 2 a )。本

章還論及樁柱及保護措施對選擇和使用

材料的影響。

1 1 . 2 護面塊石

第 9 . 3 . 2節建議設計護面時，塊石的比

重值一般應取 2 . 6，此數值符合《G S》第

2 1節的最低要求。《G S》內有關護面塊

石的規格，符合《B S 6 3 4 9 : P a r t 1》 ( B S I ,

1 9 8 4 a ) 第 5 7 . 2節的要求，只是後者容許

在非主要護面層，採用較低標準的塊石。

《B S 6 3 4 9 : P a r t 1》第 5 7 . 1節建議塊石應

為稜柱體，塊石的最大尺寸一般不應超過

其最小尺寸的兩倍，更絕對不得超過三

倍。如第9 . 3 . 4節所述，雖然在本地仍然

有可能取得少量近 1 0公噸的護面塊石，但

通常有充足供應的仍局限在6至 8公噸以

下。

1 1 . 3 回填材料

1 1 . 3 . 1 概述

因為施用外力壓實的工序十分昂貴，

88

method of placement should be capable of achieving arelatively high density fill untreated, as externalcompaction is expensive. Care must be taken with thechoice of bedding and filter materials to prevent loss ofmaterial from wave or current action and groundwatermovements. Fill material placed immediately behindseawalls above Chart Datum should be free draining toavoid the unnecessary build up of water pressures dueto tidal lag and ground water flow.

The choice of fill materials for use in a reclamationwill be greatly dependent on availability and cost. Thefour main types of fill are public dump material,selected fill from land sources, crushed rock, andmarine fill. Pulverized Fuel Ash (PFA) is anotherpossible material, but the quantities available arerelatively small, and it contains toxic contaminants. Useof PFA as fill is subject to the control of the Director ofEnvironmental Protection. For most reclamationsonly one of the above types will normally be used, butthere is no reason in principle why two or more couldnot be used on the same project, depending onavailability with regard to the required programme andcost. Brief notes on the four main types are givenbelow, with comments on particular aspects,advantages and disadvantages. Some generalcomments on fill suitability are also given herein.

In order to conserve and ensure the most economicand effective use of fill from land and marine sourcesin Hong Kong, the Fill Management Committee wasestablished in 1989 under the chairmanship of theDirector of Civil Engineering to identify and managethe supply and demand of land and marine fill sourcesfor all Government, quasi-Government and majorprivate sector projects.

11.3.2 Public Dump Material

Public dumps are operated as a service to thegeneral community to provide sites for the disposal ofsurplus material from private development andbuilding demolition sites and to ensure that good use ismade of such material, rather than it becoming a

所以，在水下進行回填時，採用的填放材

料及方法，應能讓填料在未經處理的狀態

下，仍有較高的密度。選擇底層和過濾材

料時，必須注意防止它們受到波浪、水流

作用及地下水運動而流失。置於海堤後

方，海圖基準面以上的填料，應具有良好

的排水性能，以免因潮滯和地下水作用而

增大水壓力。

回填材料的選擇，主要取決於供應情

況和成本。常用的填料有四種，包括公眾

卸泥物料、選自陸地的填料、碎石及海相

填料。研磨煤灰 ( P F A ) 是另一個可能的

選擇，但供應量較少，且含有有毒污染

物，因此，研磨煤灰在填海工程上的使用

是受到環境保護署的監管。大部分回填工

程，只採用一種填料，但原則上，多種填

料可以共用在同一工程項目中，有關的選

擇是取決於填料供應的價格和對工程進

度的影響。下文提供這四種填料的簡要說

明，同時亦論述它們的特性及優、缺點。

為保護香港陸地和海床的可用填料，

及保證它們的使用有最高的經濟效益，以

土木工程署署長為主席的填料管理委員

會在一九八九年成立。它的職能是為政

府、半官方以及大型私人機構的工程項

目，勘察填料的來源，及處理有關的供求

事宜。

1 1 . 3 . 2 公眾卸泥物料

設立公眾卸泥區是一項公共服務，為

私人發展和拆卸房屋工程製造的廢料提

供棄置場地的同時，也可有效地利用這些

材料，使資源不致浪費。公眾卸泥牌照的

條款規定，傾卸在卸泥區的物料，只限於

89

wasted resource. The material brought to a dump isrestricted by the conditions of the dumping licence toearth, inert building debris and broken rock andconcrete. Since rock and concrete over 250 mmwould impede subsequent piling, it has to be brokendown to this size or dumped in areas where nobuilding development will take place, e.g. in areaszoned for open space, road and drainage reserves,immediately behind seawalls etc.

Where there is land access to the site, public dumpmaterial will be directly end-tipped by the licensedtrucks onto the reclamation, under the control ofdump supervisors, with spreading also carried outunder the control of dump supervisors using hiredplant. Normally, no compaction is carried out otherthan that caused directly by the passage of the dumpingvehicles and spreading plant. Where possible, thetipping is carried out in two stages, firstly to a generallevel just above high water mark and later to thefinished reclamation level.

Where direct land access to the site is not available,public dump material will be conveyed via ramps intobarges, under the direction of dump supervisors, fortransport to the reclamation site by contractor.Contract arrangements should ensure that barges areavailable at all times, to avoid the need for temporarystockpiling of dump material at the barge loading site.At the reclamation site, material will either be bottom-dumped by barge or placed by grab, depending on theavailable water depth. Usually, completion of thereclamation to the required finished level is not possibleusing marine plant and direct grab placement; the useof temporary stockpiles, and distribution and finalplacement using trucks and spreading plant iscommon.

Disadvantages of using public dump materialinclude the extreme variability of the material. Thematerial is governed by the licence conditions but thequality is difficult to control, being mainly dependenton the type of development and demolition workfrom which it originates. Invariably, despite strictcontrol, timber and other floating material are

泥土、建築碎料、碎石和混凝土等。超過

2 5 0毫米的石塊和混凝土塊，會妨礙以後

的打樁工程，因此必須將其打碎，或放在

不會用於建築物發展的區域內；那些規劃

為遊憩用地、道路及排水專用範圍的區

域，或與海堤相鄰的地方，都是常見的例

子。

在有陸路連接的公眾卸泥區，領有牌

照的運泥車會直接將物料傾倒到回填

區，管理人員會監督卸泥進行，亦會利用

租用設備整平物料。通常，該等物料的壓

實，只局限於卸泥車和整平設備行駛的直

接作用，而不會有額外的安排。在可能的

情況下，卸泥應分兩階段進行﹕首階段填

至略高於高潮位，往後再填至竣工填築高

程。

在沒有陸路連接的卸泥區，卸泥車會

在管理人員的指導下，利用斜台將物料傾

倒到運泥船，再由承建商運至填海區。在

這種情況下，合約應規定，承建商須安排

任何時候都有運泥船在場運作，以免要將

廢料臨時堆置在載運站內。到達填海區的

物料，可用開底運泥船或抓斗卸下，具體

方法取決於現場水深。通常，利用海上機

械或直接用抓斗卸放，都不可能使回填達

到要求的竣工高程，所以一般須先臨時堆

存，其後再由運泥車和整平機械進行最後

鋪放。

利用公眾卸泥物料的缺點之一，是它

包含有各種不同的物料，縱使有牌照條款

的規限，其質量亦難以控制，反而主要取

決於來源地，即有關發展和拆卸工程的類

型。雖有嚴格的控制措施，木材和其他漂

浮物仍經常隨棄土從運泥車卸下，如果裝

載的是建築碎料，這問題尤為嚴重。對

90

discharged from trucks, particularly those laden withbuilding debris. Supervisors should be especiallyvigilant, and should warn drivers of such trucks.Repeat offenders should have their licences revoked.Also, sampans should be employed to pick up floatingmaterials from the water within the reclamation site.Such materials can be hazardous to shipping and areunsightly if allowed to drift into open waters; wherepossible, floating refuse booms should be used tosurround the site to contain the debris and easeremoval by the sampans.

Another disadvantage is that the rate of supply ofmaterial to a public dump, being dependent mainly onprivate development projects, is largely notcontrollable, and planning work is particularly difficultif completion dates are critical. During the operationof a public dump it is quite usual for the number oftrucks per day to vary widely. The number per day cantypically vary from lows of 100 to 200 to highs of1,000 to 1,500, with an average load per truck of 5 to8 m3. This leads to another disadvantage in that trafficcongestion at entrances and exits is unavoidable.

The main advantage of using public dumping inreclamations, other than the benefit to the community,is low cost. The only costs relate to the provision ofwheel washing facilities at the exit to the site, roadcleaning adjacent to the site, provision of booms andsampans, provision of plant to spread the material, andsupervisory staff.

11.3.3 Selected Fill

Selected fill material from a land source can beprovided either by a contractor from his own source,with the quality subject to the specification in thecontract, or from designated Government borrowareas or site formation projects. In the latter case somematerials from the designated source may not complywith the specified quality. Weathered granites fromsuch sources are generally considered to be suitable asfill for reclamations. However, weathered volcanicrocks should normally be used only above tide level,and preferably when mixed with other granular

此，管理人員應特別提高警惕，並應經常

警告有關的運泥車司機，屢次違例者的牌

照應予以撤消。同時，還應用小艇清除填

海區內的漂浮物，如任由它們漂入公共水

域，會對航運造成危害，亦有礙觀瞻。在

情況許可下，應使用懸浮垃圾欄圍 漂浮

物，以便清除。

由於公眾卸泥物料主要源自私人發展

項目，因此，其另一缺點是難以控制其供

應速度；對一些完工日期十分重要的工程

而言，籌劃工作會非常困難。而且，在公

眾卸泥區運作期間，每日到達的運泥車

數，往往有很大變化，少則1 0 0至 2 0 0輛，

多則 1 0 0 0至 1 5 0 0輛，每輛車平均裝載5至

8立方米。這又導致了另一不利情況，即

不能避免造成進出口的交通擠塞。

利用公眾卸泥物料填海的主要優點，

除方便公眾外，便是低廉的成本。開支只

須包括在出口設置車輛清洗設備，清潔附

近道路，設置浮欄，租用小艇及整平物料

設備和雇用管理人員。

1 1 . 3 . 3 經挑選的填料

源自陸上的挑選填料，既可由承建商

按合約規定的規格提供，也可取自政府指

定的採石場或地盤平整工程。取自後者的

填料，部分可能不合原定的規格。這些來

自指定地點的物料，若是風化花崗岩，一

般會符合回填材料的要求。若是風化火山

岩，因其顆粒一般都較小和塑性較高，通

常只填放在潮位以上的地方。如填放前先

與其他粒狀材料混合，效果會好一些。

91

materials, because of their typically finer grading andhigher plasticity.

11.3.4 Crushed Rock

Crushed rock, uniformly graded and withmaximum dimension about 250 mm, is suitable as afill material for reclamations, but normally will beavailable only at a reasonable cost when provided as aby-product of a major public or private sitedevelopment project involving large quantities of rockexcavation and removal. For reclamations comprisingcrushed rock, consideration should be given to reducethe maximum size and mix the crushed rock with finematerial in the top metre or so, and on the lines ofdrainage reserves, to allow easier future installation ofservices.

11.3.5 Marine Fill

The Fill Management Committee has taken overresponsibility for identifying and investigating marineborrow areas, and for allocation of fill to individualprojects. The use of marine fill can be economicallyviable for a reclamation project where a marineborrow area can be allocated by the Fill ManagementCommittee within a reasonable distance of the site andwhere the size of the project justifies the use ofsophisticated dredgers with high mobilisation costs.Such plant can dredge marine deposits at relatively lowunit cost. Trailer dredgers can deposit marine sand inthe reclamation by bottom dumping or by pumping,depending on the access and water depth available.The rate of formation of the reclamation can beextremely rapid compared with the use of other typesof fill, and often several trailer dredgers can be used onthe same site if necessary.

11.4 Concrete

11.4.1 Reinforced and Prestressed Concrete inGeneral

Recommendations for reinforced and prestressed

1 1 . 3 . 4 碎石

均勻級配且粒徑不超過 2 5 0毫米的碎

石，是合適的回填材料，但通常只有當這

些碎石是牽涉大規模岩石挖掘的發展工

程的副產品時，才能以合理的價格獲得。

用碎石填築時，應考慮減低填料的最大粒

徑，並在回填頂部約一米厚的部分，或專

用排水區地方，將碎石與細粒材料混合，

以方便將來安裝各類管線設施。

1 1 . 3 . 5 海相填料

填料管理委員會負責勘察和研究海上

採泥區，並分配填料予各項工程。對於填

海工程來說，由於利用現代化挖泥機挖掘

海相沉積物的單位成本較低，如果填料管

理委員會分配使用的海上採泥區接近工

地，而工程的規模又能承擔這些現代化挖

泥機的高昂調遣費用的話，採用海相填料

在經濟上是可行的。耙吸挖泥船可開底或

用泵在填海區內卸下海相填料，使用的方

法應視乎航道情況和水深而定。利用海相

填料回填，可以比採用其他材料快捷很

多，而且必要時，更可同時使用數艘耙吸

挖泥船在同一工地內操作。

1 1 . 4 混凝土

1 1 . 4 . 1 鋼筋混凝土和預應力鋼筋混凝土

除了不會直接暴露於海相環境的部分

92

concrete, except where protected from directexposure to the marine atmosphere, are in line withthose given in Chapter 6 for suspended deck structuresand are as follows :

(a) Minimum characteristic strength 45 MPa

(b) Maximum free water/cement ratio 0.40

(c)(i) Nominal concrete cover fully 60 mmimmersed, and in tidal and splashzones

(ii) Nominal concrete cover above 50 mmsplash zone

It is considered that criteria (a) and (b) above shouldapply irrespective of whether the concrete is fullyimmersed, within the tidal or splash zones or locatedabove the normal splash zone. For concrete within thetidal and splash zone, crack widths under typicalaverage long term loading conditions, as described inChapter 6, should be limited to 0.1 mm. Whereprotected from direct exposure to the marineatmosphere, reinforced concrete should comply withthe recommendations given in BS 8110:Part 1 (BSI,1985a) for "moderate" exposure conditions.

11.4.2 Durability

The durability of reinforced concrete dependsfundamentally on the quality and impermeability of theconcrete, which prevent steel reinforcement fromcorroding. Normally concrete provides an alkalineenvironment which slows corrosive reactions. Thebest method of ensuring that this natural alkalineprotective mechanism is maintained is by providingconcrete which has the lowest possible permeability.This can be obtained by adopting mixes designed toproduce concrete of the highest practicable density.However, care should be taken that requirements forhigh strength and low permeability do not result in theworkability being restricted to less than that requiredfor adequate compaction. The recommendation in

外，有關鋼筋混凝土和預應力鋼筋混凝土

的標準是與第六章有關在承台式結構使

用的混凝土的建議一致的，如下所示﹕

( a ) 最小特性強度 4 5 M P a

( b ) 最大水 /水泥比值 0 . 4 0

( c ) ( i ) 水下、水位變動及 6 0 m m

浪濺區的混凝土保

護層額定厚度

(ii) 浪濺區以上的混凝 5 0 m m

土保護層額定厚度

上述標準中的 ( a ) 和 ( b )，適用於各部

位的混凝土，包括水下、水位變動和浪濺

區，以及正常浪濺區以上的地方。水位變

動和浪濺區的混凝土，在典型的長期荷載

條件下，其裂縫寬度，如第六章所述，應

限制在 0 . 1毫米以下。在不直接暴露於海

相 環 境 的 地 方 ， 鋼 筋 混 凝 土 應 符 合

《B S 8 1 1 0 : P a r t 1》 ( B S I , 1 9 8 5 a ) 中對

「中度」暴露條件的建議。

1 1 . 4 . 2 耐久性

鋼筋混凝土的耐久性，主要取決於能

防止鋼筋銹蝕的混凝土質素和不透水

性。通常，混凝土提供一個延緩銹蝕作用

的鹼性環境，保持這一自然鹼性防護機制

的最好方法，是採用透水性最低的混凝

土，這可以透過成分設計，製造最高密度

的混凝土來達致。但應注意，要求強度

高、透水性低的同時，其和易性不應低於

混凝土能被充分搗實的要求。上述標準

( b )的 0 . 4 0的最大水/水泥值是出自混凝

土技術常務委員會對海事鋼筋混凝土工

程而作出的暫用混凝土規格建議。實際工

程上，採納這個偏低的水 /水泥比值時，

許多結構和構件，特別若是大量加筋的

93

criterion (b) above for a maximum free water/cementratio of 0.40 is taken from the Interim ConcreteSpecification for Reinforced Concrete Structures inMarine Environment issued by the StandingCommittee on Concrete Technology. In practice, theuse of such a low water/cement ratio will require theuse of a water reducing admixture, or superplasticizer,for many structures or elements, particularly thoseheavily reinforced, to ensure adequate workability andcompaction. Particular care needs to be taken whendetailing reinforcement to avoid congestion so that theconcrete can be easily placed and subsequentlycompacted. It has to be noted that adequate curing ofthe concrete is essential to achieve the desired durability.For reinforced or prestressed concrete work in thetidal zone, precast units should be used whereverpossible, with the minimum of in situ concreteconnections; the use of epoxy coated reinforcementmay be considered, and prestressed concrete should beavoided.

Correct use of PFA as a cement replacement canreduce permeability and increase resistance to sulphateattack.

11.4.3 Unreinforced Concrete

For unreinforced concrete in massive sections, suchas precast concrete seawall blocks and backingconcrete for granite facing in seawalls, the use ofconcrete with a minimum characteristic strength of20 MPa has been shown to be successful, with nosignificant maintenance problems. The continued useof such concrete for massive sections is recommended,irrespective of whether the concrete is fully immersedor within the tidal or splash zones, provided theconcrete is actually placed 'in the dry'. It should benoted that Clause 6.2.4.2 and Table 6.2 of Part 1 ofBS 8110:Part 1 recommend the use of higher gradesof concrete to 'ensure long service life' forunreinforced concrete under all exposure conditionsother than 'mild'. It is suggested that theserecommendations should be followed forunreinforced concrete except for massive sectionsreferred to above.

話，須使用減水劑或塑化劑，以確保混凝

土有足夠的和易性和密實性。佈筋時，應

特別注意鋼筋不要過密，以便於混凝土灌

注和搗實。必須注意的是，充分養護混凝

土是達到理想耐久性的基本條件。在水位

變動區的鋼筋混凝土或預應力鋼筋混凝

土結構，應盡量使用預製構件，並盡量減

少採用現場澆注混凝土的接合點。此外，

也可考慮使用加上環氧樹脂塗層的鋼

筋，以及避免使用預應力鋼筋混凝土。

正確地使用研磨煤灰來代替水泥，能

降低混凝土的透水性，也可提高對硫酸鹽

侵蝕的抵抗力。

1 1 . 4 . 3 無配筋混凝土

據以往經驗，在大體積的構件中，（如

用於海堤的混凝土預製塊和花崗岩面層

後的堤背混凝土），曾廣泛地使用最小強

度級別為 2 0 M P a的無配筋混凝土，而沒

有導致較大的維修問題。因此，建議無論

是位於水下、水位變動還是浪濺區的大體

積的構件，仍應繼續使用此級別的混凝

土，但澆注必須在「乾燥狀態下」進行。

應該注意的是，《 B S 8 1 1 0 : P a r t 1》第

6 . 2 . 4 . 2節和表 6 . 2建議，除了處於「溫和」

暴露條件的部分外，構件中的無筋混凝土

都應屬於較高的級別，以確保其在所有暴

露條件下仍能保持較長的使用期。因此，

建議除上述大體積構件外，其他無配筋混

凝土也應遵照這些指引。

94

Partial replacement of cement by PFA in thicksections will reduce the effects of heat of hydration.Replacement of up to 50% of the cement may beconsidered if early strength is not critical.

11.4.4 Underwater Concrete

Guidance on underwater concrete is given inSection 58.11 of BS 6349:Part 1. The use of epoxycoated reinforcement and a waterproofing admixturein the concrete mix are recommended. Reinforcedconcrete placed underwater should only be used whereabsolutely necessary, because of the difficulties ofensuring sound results and the problems of inspection.In particular, the use of concrete placed by tremie forforming heavily reinforced small elements such as pilecaps within the fully immersed or tidal zones should beavoided, by making full use of precast units orrequiring the use of watertight steel shutters, extendedin height as necessary, to enable the concrete to beplaced 'in the dry'.

For driven steel tubular piles which are intended tobe filled with reinforced concrete to one or two metresbelow sea-bed level, it is usually possible, afterexcavation, to form a plug in the bottom and pumpthe inside of the pile dry. This approach is preferred tothe use of concrete placed by tremie. For boredconcrete piles with a steel tubular casing, it will notusually be possible to pump the inside of the pile drybefore concreting, and there will be no alternative tousing reinforced concrete placed by tremie. For suchpiles, it is recommended that a minimum of threegalvanised steel tubes, of a diameter suitable forpossible future sonic testing, are cast in the concretefrom founding to cut off level.

It should be noted that concrete placed under watershould not be designed for a characteristic strengthgreater than 25 MPa. It is recommended that thislimitation should apply to bored piles formed byreinforced concrete placed by tremie due to the defectswhich can occur, but a higher grade of concrete shouldbe specified in order to achieve this condition.

在較厚的部分用研磨煤灰代替部分水

泥，會降低水化熱作用。如果早期強度要

求不高，可考慮使用研磨煤灰代替高達5 0

﹪的水泥。

1 1 . 4 . 4 水下混凝土

《B S 6 3 4 9 : P a r t 1》第 5 8 . 1 1節提供了

有關水下混凝土的指引。建議使用環氧樹

脂塗層鋼筋和在混凝土拌合料中添上防

水外加劑。只有在絕對必要時，方可進行

水下澆注，因為水下澆注難以保證其效果

良好，檢測亦十分困難。應特別注意的

是，製造處於水下和水位變動區且大量加

筋的小構件（如樁帽）時，要避免用豎管

澆注混凝土，而應盡量利用預製件或防水

鋼模板，必要時可將模板加高，以確保混

凝土在「乾燥狀態下」澆注。

如果計劃是在鋼管打入樁內填入鋼筋

混凝土，至海床以下1至 2米，通常可在挖

方工序完成後，在樁底形成管塞，並將樁

管泵乾，這方法比用豎管澆注混凝土更

佳。至於使用鋼套管的鑽孔灌注樁，一般

不可能在澆注混凝土之前將樁管泵乾，而

必須使用豎管。在這情況下，建議在澆注

混凝土時，安裝至少三支從基底到截止高

程的鍍鋅鋼管，該等鋼管直徑應配合將來

可能進行的音波試驗。

應該注意的是，水下澆注的混凝土，

其設計特徵強度不得高於2 5 M P a。考慮

到用豎管澆注的鋼筋混凝土鑽孔灌注樁

可能出現的誤差，建議此項規定也應用於

該類型樁。同時，為了要符合這項規定，

應該指定使用級別較高的混凝土。

95

11.4.5 Design

It is recommended that BS 8110:Part 1 shouldform the basis for the design of concrete structures.Information on partial load factors for suspendeddeck structures is given in Section 6.2; this can be usedas a guide for other types of concrete structure.

11.5 Steel

11.5.1 Structural Steel in General

Structural steel in marine structures should normallybe weldable structural steel complying with BS7668:1994 (BSI, 1994d), BS EN 10137, Parts 1, 2 &3:1996 (BSI, 1996a, b & c), BS EN 10113 Parts 1, 2 &3:1993 (BSI, 1993a, b & c), BS EN 10029:1991 (BSI,1991a), BS EN 10155: 1993 (BSI, 1993d), or BS EN10210-1 (BSI, 1994b) as appropriate. The use ofBS 449:Part 2 (BSI, 1969) for the design of steelelements and structures is recommended, withincreased permissible stresses for certain loadingconditions, in line with the suggestions given in Chapter6 for suspended deck structures.

11.5.2 Corrosion Protection

For steel structures and major steel elements,corrosion protection or allowances for metal lossesdue to corrosion, or both, will be a majorconsideration. It should be noted that the advice inTable 22 of BS 6349:Part 1, which gives typical upperrates of corrosion for structural steels in maritimeconditions in the United Kingdom, is notrecommended for use in Hong Kong. Hong Kongwaters are relatively warm, and contain variouspollutants whose effect on steel is generally unknown.In many sites, the presence of anaerobic sulphate-reducing bacteria, which can greatly increase normalsteel corrosion rates, is also suspected. In the absenceof full scale long-term tests covering metal loss fromcorrosion in Hong Kong waters, it is recommendedthat all structural steelwork above sea-bed level,

1 1 . 4 . 5 設計

建 議 設 計 混 凝 土 結 構 時 ， 應 以

《B S 8 1 1 0 : P a r t 1》為依據。第 6 . 2節列

出的承台結構之分項荷載系數，亦可作為

其他類型結構設計時的參考。

1 1 . 5 鋼材

1 1 . 5 . 1 結構鋼概述

海事結構所用的鋼材，一般應符合 BS7668:1994 (BSI, 1994d), BS EN 10137, Parts1, 2 & 3:1996 (BSI, 1996a, b & c), BS EN10113 Parts 1, 2 & 3:1993 (BSI, 1993a, b & c),BS EN 10029:1991 (BSI, 1991a), BS EN10155: 1993 (BSI, 1993d), or BS EN 10210-1 (BSI, 1994b) 規定的可焊結構鋼。當設計鋼構件和鋼結構時，建議使用《 B S 4 4 9 :

P a r t 2》 ( B S I , 1 9 6 9 )規定的標準，同時

在某些荷載條件下，根據第六章關於承台

結構的建議，增加容許應力。

1 1 . 5 . 2 銹蝕防護

對於鋼結構和大型鋼構件來說，銹蝕

防護和預計銹蝕量是很重要的因素。應注

意的是，《B S 6 3 4 9 : P a r t 1》 表 2 2是依

據鋼結構在英國的海相條件下的典型銹

蝕率上限而制定的，因此，不應在香港應

用。香港水域相對地較溫暖，含有各種污

染物，它們對鋼材的影響，目前尚未被清

楚確定，況且，在香港許多地方，懷疑存

在著一種使鋼蝕率大幅提高的厭氧抗硫

酸鹽細菌。現在尚未有全面就香港水域銹

蝕造成的金屬損失進行過長期試驗，在這

情況下，建議海床以上所有的結構鋼，無

論在水下、水位變動及浪濺區或甚至是位

於浪濺區以上的，均應按設計使用期進行

全面銹蝕防護。至於鋼樁在海床以下部

分，如未有銹蝕防護，可以假定其外層表

面每年的銹蝕量為 0 . 0 5毫米。關於銹蝕防

96

whether fully immersed, within the tidal or splashzones, or generally above the splash zone, is fullyprotected against corrosion for the design life of thestructure. Below sea-bed level, an allowance forcorrosion loss of 0.05 mm per year on the outside faceof steel piles is considered reasonable, if no corrosionprotection is carried out within this zone. For guidanceon protective measures which can be taken againstcorrosion, see Section 11.9.

11.5.3 Use of Stainless Steel

Section 21 of the General Specification for CivilEngineering Works (Hong Kong Government, 1992a)requires stainless steel for elements in marine workssuch as chains, railings, cat ladders, pumphouse screensand screen guides, mooring eyes and other fittings tobe austenitic stainless steel grade 316 complying withBS 970:Part 1 (BSI, 1996d), BS 1449:Part 2 (BSI,1983), or BS EN 10088: Parts 1, 2 & 3 (BSI, 1995a, b& c) as appropriate. It should be noted that thecommonly available grade 304 stainless steel is notsuitable for use in a marine environment due to thepresence of chlorides. The selection of the correctgrade of stainless steel at the design stage is mostimportant, as corrosion in stainless steel members andfasteners may not be readily evident. In stresscorrosion cracking, corrosion occurs along grainboundaries, and there may be no corrosion productevident, or only slight staining. A visual examinationmay not show this cracking, even though the memberor fastener is about to fail.

11.5.4 General Guidance

General guidance on the use of structural steel andother metals in marine structures is given in Clause 59of BS 6349:Part 1. Important points to note are asfollows :

(a) Fabrication details should be kept as simple aspossible and should be designed to avoidcorrosion and facilitate maintenance.

(b) Tolerances for on-site connections should be

護措施的指引，可參考第 1 1 . 9節。

1 1 . 5 . 3 不銹鋼的使用

《G S》第 2 1節規定海事工程構件使用

的不銹鋼，須符合《B S 9 7 0 : P a r t 1》 ( B S I ,

1 9 9 6 d ) ，《B S 1 4 4 9 : P a r t 2》 ( B S I , 1 9 8 3 )

或《B S E N 1 0 0 8 8 : P a r t s 1 , 2 & 3》 ( B S I ,

1995a , b & c )奧氏體不銹鋼級別 3 1 6的規

格。這些構件包括鏈條、圍欄、爬梯、泵

房欄污柵、欄污柵導框、繫船環及其他裝

置。應該指出的是，常用的 3 0 4級別不銹

鋼，並不適合在含氯化物的海相環境中使

用。因為不銹鋼構件和固緊件的銹蝕可能

不太明顯，所以設計時選擇適當等級的不

銹鋼非常重要。若因應力引起了銹蝕裂

化，銹蝕會沿顆粒邊緣出現，這時可能沒

有明顯的銹蝕產物，或只有少許銹斑，因

此，即使構件或固緊件已近乎損壞，使用

目測亦未必會發現裂紋。

1 1 . 5 . 4 一般指引

《B S 6 3 4 9 : P a r t 1》第 5 9節載述了在海

事結構中採用鋼和其他金屬的一般指

引。應注意的重點如下﹕

( a ) 裝配細節應盡量簡單，其設計要能

避免銹蝕及便於維修，

( b ) 在海相環境下工作困難，因此，現

場連接工序的容許誤差應較寬裕，

97

generous because of the difficulties associatedwith working in a marine environment.

(c) As much prefabrication as possible should beundertaken, taking advantage of mechanisedwelding and early painting under factory-controlled conditions.

(d) Steel embedded in concrete is cathodic relativeto the same steel in seawater, and rapidcorrosion will therefore occur at the interface ofa partly embedded member unless specialtreatment is carried out, e.g. use of sacrificialanodes and impressed currents.

(e) Chemical composition of steels has lessinfluence on corrosion rates in a marineenvironment than physical factors such as theroughness of the surface finish of the steel andthe presence of holes and re-entrant corners, allof which tend to promote the formation ofgalvanic corrosion cells.

11.6 Timber

11.6.1 Types of Material

Section 21 of the GS requires timber for fenders tobe "Selangan Batu" (also known as "Yacal" and"Balau") or similar species of hardwood, visually stressgraded to the Hardwood Structural (HS) grade ofBS 5756 (BSI, 1980), and to satisfy the strengthrequirements for strength class SC 8 or SC 9 ofBS 5268:Part 2 (BSI, 1991b).

11.6.2 Design Stress

For the design of timber fenders and walings, it isrecommended that the grade stresses and moduli ofelasticity for strength class SC 7 given in Table 9 ofBS 5268:Part 2 should be used, after application ofthe modification factor K 2 for wet exposureconditions given in Table 16 of BS 5268:Part 2. It

(c) 盡可能使用預製方法，俾能充分利

用在廠房調控環境下進行機械焊接

和完成早期塗層的優點，

( d ) 鋼件埋置在混凝土的部分，相對於

浸在海水的部分來說屬於陰極，因

此，除非經過特別處理，一個只有

部分埋藏在混凝土內的鋼構件，會

在交接處被迅速腐蝕。使用消耗陽

極和外接電流，是這些特別處理的

其中一種，

( e ) 在海相環境下，鋼的化學成分對銹

蝕率的影響，不及物理因素重要，

例如鋼表面的粗糙加工、孔隙和陰

角的存在等，都會導致銹蝕電池體

的產生。

1 1 . 6 木材

1 1 . 6 . 1 木材種類

《G S》第 2 1節要求護舷設備使用的木

材應為「杪木」( S e l a n g a n B a t u、Y a c a l 或

B a l a u )，或類似的硬木，亦須經目測判

別應力等級，符合《B S 5 7 5 6》 ( B S I , 1 9 8 0 )

規定的硬木結構 ( H S ) 級別。另外，木材

應符合《B S 5 2 6 8 : P a r t 2》 ( B S I , 1 9 9 1 b )

強度級別 S C 8和 S C 9的規格。

1 1 . 6 . 2 設計應力

設計防撞和橫向護木時，建議採用

《B S 5 2 6 8 : P a r t 2》表 9列出，等級為S C 7

的木材的等級應力值和彈性模量計算強

度，再乘以《B S 5 2 6 8 : P a r t 2》表 1 6列出

在濕潤條件下的修正系數 K 2。應該注意

的是，表 9中的等級應力值，只適用於在

長期荷載作用下的情況。當護木受到其他

98

should be noted that the grade stresses given inTable 9 apply to long term loading, and Table 17 ofBS 5268:Part 2 gives details of the modificationfactor K3 by which these stresses can be multiplied forvarious other durations of loading. It is recommendedthat any combination of loading with berthing or waveloads may be considered 'very short term' for thepurposes of assessment of a value for K3 from Table17.

Note should be taken of Clause 14.6 ofBS 5268:Part 2, which covers the depth modificationfactor K7 which is used for adjusting the gradebending stresses given in Table 9, where the depth ofthe member being designed is other than 300 mm.

Clause 2.8 of BS 5268:Part 2 defines the gradestress as the stress which can safely be permanentlysustained by material of a specific section size and of aparticular strength class or species and grade. Byimplication, grade stresses, adjusted where appropriateusing the modification factors, should be used for thedesign of timber structures or timber members, whereit is required that the structure or member should beable to last without replacement for the design life ofthe structure. It is not considered necessary oreconomical to design a timber fendering system for thefull design life of a suspended deck structure, becausereplacement of individual members is relatively simpleand inexpensive, and damage or failure of part of thefendering system will normally result in normal minordamage, if any, to the suspended deck structure itself.For timber, the variation in material properties withinany strength class is particularly large, and to designtimber fendering systems based on the grade stress,which is based on the 5% lower exclusion values ofstrength, would not make the best use of the material,and would result in larger timber sections, steel boltsand fixings being required than have been used in thepast and are commonly available.

11.6.3 Loading Factors

For the reasons given above, it is recommended

荷載歷時作用時，可以將這應力強度再乘

以《B S 5 2 6 8 : P a r t 2》表 1 7列出的修正系

數K 3。利用表 1 7估算K 3值時，任何包括

靠泊力或波浪力的荷載組合，都應視為

「非常短暫」。

如果設計的護木厚度不是 3 0 0毫米，應

參考《B S 5 2 6 8 : P a r t 2》第 1 4 . 6節的論述，

其中涉及的厚度修正系數 K 7，可用來調

整列於表 9的等級彎曲應力。

《B S 5 2 6 8 : P a r t 2》第 2 . 8節註明等級

應力的定義是：具有指定剖面尺寸、屬於

特定類別和強度等級的材料所能長期承

受的應力。因此，以適當修正系數調整後

的等級應力，可用來設計木料結構和構

件，使其於設計使用期內不必更換。對承

台結構而言，若護木系統採用與結構相同

的設計使用期，是既不必要也不經濟的，

因為更換護木系統的個別構件較為簡單

和便宜，而且，縱然部分護木系統損壞

了，通常也只會對整個承台結構做成輕微

影響。縱是同一強度等級的木材，其特性

變化也會很大，木材的等級應力是根據除

去最低 5﹪後強度所對應的應力而確定

的。以這等級應力來設計的防撞護木系

統，不能最有效地利用各類物料，所需的

護木剖面、鋼螺栓和固定件都會比過去所

用的要大，也不易有供應。

1 1 . 6 . 3 荷載系數

綜上所述，設計護木系統時建議提高

護木的容許應力，方法是將根據《B S 5 2 6 8 :

99

that the permissible stresses obtained from the gradestresses and modification factors in BS 5268:Part 2should be increased by multiplying by a design factorfor the design of timber fendering systems. Suggestedvalues for this design factor for different members andloading conditions are as follows :

Loading Condition Factor

Normal 1.6Extreme 2.0Temporary 2.0Accident 2.4

The factors proposed above relate to fenderingsystems for typical suspended deck structures. At thediscretion of the designer, these factors may beincreased or decreased to suit the structure use andlocation. For a public pier with relatively low use, forexample, where the design vessel is not expected toberth frequently, an increase in the factors of up to 20%may be considered, whereas for a heavily used ferrypier, where the design vessel will berth frequently, adecrease in the factors of up to 20% would be morereasonable.

When designing timber fenders for public piers andferry piers, for vessels with displacement not exceedingabout 1500 t, it is normal to assume for the designcondition that the vessel contacts two vertical fenderssimultaneously, provided that the clear distancebetween the fenders is not greater than about800 mm.

It is not normal, when designing timber fenders forpublic piers or ferry piers, to make an allowance formaterial loss due to wear of the faces of the fenders bythe vessels during berthing. However, such anallowance should be considered by the designer whendesigning a ferry pier which is expected to be heavilyused by vessels with steel-faced rubbing or berthingstrips. In such a situation, the fender design should bechecked with the ferry operator, but in any event it isnot recommended that the fender size should beincreased to an extent that this results in a size of fenderand fixing outside the normal range.

Par t 2》的等級應力和修正系數得出的容

許應力，乘以一設計系數。不同構件和荷

載條件下，建議使用的設計系數值如下﹕

荷載條件 系數

正常 1 . 6

極端 2 . 0

臨時 2 . 0

意外 2 . 4

這些系數適用於典型的承台結構的防

撞系統。設計人員可以按結構的使用情況

和所處的位置，修訂這些系數的值。對於

使用率較低的公用碼頭，如設計船型不經

常靠泊，系數可加大2 0﹪；而對於使用率

高，設計船型經常會靠泊的渡輪碼頭，將

系數減少 2 0﹪較為適當。

設計公用和渡輪碼頭的護木時，若船

舶排水量不超過 1 5 0 0公噸，護木之間的

淨距又不超過 8 0 0毫米，通常會假設船舶

同時接觸兩條垂直護木。

在設計公用和渡輪碼頭護木時，通常

不會考慮因船隻靠泊而引起的表面磨

損。不過，如果預計一些裝了鋼面層護舷

邊條的船隻將會頻密地靠泊時，設計人員

應考慮加上這些磨損的預留量，這些護木

設計應與渡船公司檢核，但建議加大後的

護木和配件，都應在常用的規格之內。

100

11.7 Rubber

Section 21 of the GS requires rubber for fenders tobe resistant to aging, weathering and wearing, to behomogeneous, free from any defects or impurities,pores or cracks and to have certain defined propertiesas covered by parts of BS 903 (BSI, several parts, 1976to 1995). Sources of information on types of rubberfenders are given in Section 4.13. Information given inthe major manufacturers' catalogues concerning fenderreaction, deformation and energy characteristics maygenerally be accepted with confidence. Beforefinalising a rubber fender design, advice should alwaysbe sought from one or more of the major reputablesuppliers regarding suitability for the project.Wherever possible, rubber fenders should be selectedor specified to match existing fenders, to minimise thedifferent types of fenders required to be kept in stockfor future maintenance.

11.8 Piles

11.8.1 General

Section 8 of the GS covers piling works. Forgeneral information on types of piles and theirsuitability for different ground conditions, locationsand types of structure, see Section 7.4 ofBS 8004 (BSI, 1986) and Chapter 2 of Tomlinson(1987). Useful information on piles in maritime worksis given in Clause 61 of BS 6349:Part 1.

11.8.2 Driven Concrete Piles

For the types of marine structure covered by thisManual, the choice of bearing pile will generally belimited to driven prestressed concrete, driven tubularsteel and bored cast in situ concrete piles, and minipiles.Driven prestressed concrete piles have beensuccessfully used in local conditions for many years, buthave disadvantages related to loading andsize/weight/length limitations, problems with

1 1 . 7 橡膠

《G S》第 2 1節要求橡膠護舷既能耐老

化、耐風化和耐磨損，又要均質、無缺陷、

無雜質、無孔隙和無裂紋，且還應具備

《B S 9 0 3》 ( B S I , s e v e r a l p a r t s , 1 9 7 6至

1 9 9 5 ) 要求的某些特性，第 4 . 1 3節載述了

有關橡膠護舷類型的資料來源。主要生產

商在其產品目錄裏列出的資料，包括護舷

的反作用力、變形和吸收能量特性等，通

常都可以信賴。在確定橡膠護舷的設計之

前，應先向信譽良好的主要供應商查詢，

讓他們就設計是否適用於該項工程提供

意見。選擇橡膠護舷或訂定其規格時，應

盡量與沿用的類型配合，以減少用作維修

儲備的各類型護舷數目。

1 1 . 8 樁

1 1 . 8 . 1 概述

《G S》第 8節論述了打樁工程。關於

各類型樁的一般資料，及它們在不同地

質、結構位置和形式等情況下的適用性，

可參閱《B S 8 0 0 4》 ( B S I , 1 9 8 6 ) 第 7 . 4節

和T o m l i n s o n ( 1 9 8 7 ) 第二章。《B S 6 3 4 9 :

Par t 1》第 6 1節載有樁在海事工程應用的

實用資料。

1 1 . 8 . 2 混凝土打入樁

本手冊提及的海事結構，其支承樁一

般會選擇預應力鋼筋混凝土打入樁、鋼管

打入樁、現澆混凝土鑽孔灌注樁以及小型

樁。多年來，在香港採用預應力混凝土打

入樁都相當成功，它的缺點是在荷載和尺

度 /重量 /長度方面的限制，接高、穿過

大石和障礙物的困難，及因須預製而影響

施工進度的問題等。近年，由於濱海區土

地的需求很大，在該等地區找尋一個適合

的大型預製場，往往非常困難。

101

extensions, driving through boulders and obstructions,and can give programming problems due to the needfor precasting. The provision of a suitably large worksarea for a precasting yard with marine frontage isbecoming increasingly difficult to arrange as pressurefor waterfront sites increases.

11.8.3 Tubular Steel Piles

Driven tubular steel piles are becoming increasinglywidely used, due to their flexibility and general ease ofuse related to range of load, diameter, length, ease ofextension and storage. Steel tubular piles can be eitherfully protected against corrosion or filled withreinforced concrete after driving, with the steel tube inthis case often being left unprotected above seabedlevel. To reduce the possibility of long termmaintenance problems, preference is for steel tubularpiles to be infilled with concrete to at least belowseabed level and for the steel tube above seabed levelto be considered as sacrificial and ignored for designpurposes, the length of pile above seabed levelbecoming in effect a reinforced concrete cast in situ pile.Such reinforced concrete should follow therecommendations of Section 11.4, with the increase indurability provided by the steel 'casing' considered anadditional benefit. With driven tubular steel piles, it ispossible to overcome problems with obstructions, bychiselling inside the pile if driven open ended, or bytemporary extraction, followed by the installation of anoversize casing through the obstruction and subsequentredriving within the casing.

11.8.4 Bored Piles

Bored cast in situ concrete piles should be avoidedwhere possible because they generally require the use ofa tremie, as discussed in Section 11.4, although any lossof durability caused by the use of concrete placed bytremie will be offset to some extent by the presence ofthe 'sacrificial' steel casing above seabed level. Theadvantages of this type of pile relate to the ability tocarry high loads and the relative ease with whichboulders and obstructions can be dealt with. High

1 1 . 8 . 3 鋼管樁

鋼管打入樁已被日益廣泛採用，原因

是其承載力、直徑和長度的範圍有彈性及

方便使用，接高和堆存亦較為容易。鋼管

樁可進行全面防蝕處理，也可於打樁後填

注鋼筋混凝土，這通常可令位於海床以上

的鋼管不用再加保護。為減少長期維修的

問題，應在鋼管樁內灌入混凝土，至少到

達海床以下，並把海床以上的鋼管視為可

消耗的部分，設計時不將其計算在內。實

際上，這會令樁在海床以上的部分變為鋼

筋混凝土現澆樁。鋼筋混凝土的選用，應

遵照第 1 1 . 4節的建議，而因鋼管「套」的

存在而提高的耐久性，可視為額外益處。

鋼管打入樁能克服障礙物產生的問題。若

用的是開口樁，可在管內進行開鑿；也可

臨時抽出樁，然後用一加大的套管穿過障

礙物，再在套管內將樁打入。

1 1 . 8 . 4 鑽孔灌注樁

如第 1 1 . 4節所述，澆注鑽孔現澆混凝

土樁時，一般要使用豎管。儘管海床以上

的「可耗性」鋼套管，會在一定程度上抵

消由豎管澆注混凝土所減低的耐久性，在

可能情況下，仍應避免使用這類樁。它的

優點是承載力高和較容易穿過大石及障

礙物。最大的缺點是造價高，原因是需用

專用設備在水上安裝直徑較大的套管，並

要在套管內部挖方。

102

cost, due to the need to use specialist plant to install alarge diameter casing over water, and to excavatewithin this casing, is usually a major disadvantage.

11.8.5 Fender Piles

Fender piles should, where possible, be dispensedwith by designing structures and fendering systems insuch a way that berthing loads are distributed directlyto the main structure. Where fender piles areconsidered essential, they should be of steel orprestressed concrete and should be capable of beingreplaced during the design life of the structure, becauseof the possibility of accidental damage. Suchreplacement can best be arranged by locating thefender piles in sockets at or slightly below seabed level,rather than by driving the fender piles into the seabed asfor normal driven bearing piles. Such sockets can beformed in precast concrete blocks surrounded by andresting on rubble. Replacement of driven fender pilescan be extremely difficult or unsatisfactory due to theproximity of the structure, often with an overhangingor projecting roof or upper deck, and to disturbanceof the seabed due to the driving and extraction of theoriginal fender piles.

11.8.6 Sheet Piles

For the types of marine structure covered by thisManual, permanent sheet piles will not commonly beused. Where they are used, the common types ofinterlocking steel sheet piles will usually be suitable.Comments are given in Section 7.2 regarding materialloss and corrosion protection for steel sheet piles.

11.9 Protective Measures

11.9.1 General

Information on protective measures which can beused to stop or reduce deterioration in marine

1 1 . 8 . 5 護舷樁

為了避免使用護舷樁，設計時應盡量

讓靠泊荷載直接傳到主要結構上。若必須

使用護舷樁時，材料應選擇鋼或預應力鋼

筋混凝土，並且要保證在設計使用期內因

意外而損毀時可以更換。更換時，最好的

方法是將護舷樁置於海床或稍低於海床

的承口上，而不要像通常打入承載樁那樣

打入海底，承口可用混凝土預製，置於堆

石上，用毛石圍繞。護舷樁一般都緊連結

構，其上可能有垂懸或伸出結構，也可能

有上層面板，加上打樁和拔樁時會擾動海

床，所以更換護舷樁是極其困難的，亦不

易得到令人滿意的效果。

1 1 . 8 . 6 鋼板樁

永久性鋼板樁並不常應用於本手冊內

提及的海事結構。實際應用時，常見的連

鎖鋼板樁通常都會適用。第 7 . 2節論述了

鋼板樁的銹蝕損失和防護措施。

1 1 . 9 防護措施

1 1 . 9 . 1 概述

《B S 6 3 4 9 : P a r t 1》第 6 8節闡述了抑制

或減慢海事結構損壞的防護措施。第 6 . 5

節、 7 . 2節和 1 1 . 5節，分別論述了鋼材在

本地情況下的銹蝕損耗。

103

structures is given in Section 68 of BS 6349:Part 1(BSI, 1984a). Comments on corrosion losses for steelin local conditions are given in Sections 6.5, 7.2 and11.5.

BS 5493 (BSI, 1977) gives valuable guidance on thechoice and specification of coating systems available,although it should be noted that the definitions ofenvironment and recommendations for coatings areprimarily related to conditions in the United Kingdom;local conditions are likely to be more corrosive, duemainly to higher air and sea temperatures, andhumidity.

11.9.2 Life of Protective Coatings

Where access for repair or maintenance is notpossible or extremely difficult, the initial protectivecoating will be required to have the same life as thestructure. Where access for repair or maintenance isreadily available, the life requirement of the initialprotective coating is based on the time which canelapse before major or general maintenance of thecoating becomes necessary. That time is referred to asthe 'time to first maintenance' in BS 5493. BS 5493gives the following recommendations for commonprotective coatings in United Kingdom conditions forthe seawater splash zone, frequent salt spray, orimmersion in seawater :

Typical Time to General Description withFirst Maintenance Total Nominal Thickness

(µm)

Long (a)Galvanising (85 min.) plus(10 to 20 years) Coal Tar Epoxy(150)

(b)Coal Tar Epoxy (450)

Medium (a)Galvanising (140)(5 to 10 years) (b)Coal Tar Epoxy (350)

Short (a)Galvanising (85 min.)

《B S 5 4 9 3》 ( B S I , 1 9 7 7 ) 提供了選擇

和規範塗層系統的指引，但仍須指出的

是，其中關於環境因素的界定和塗層的建

議，都是基於英國的情況；在本港，由於

氣溫和海水溫度較高，濕度大，所以可能

腐蝕性會更高。

1 1 . 9 . 2 防護層的使用期

在維修和保養很困難，甚或是不可能

的地方，初始的防護層應與結構具有相同

的使用期。在便於維修和保養的地方，初

始防護層的使用期，取決於須為該塗層作

全面保養前的時間，《B S 5 4 9 3》稱這為

「首次保養期」。《B S 5 4 9 3》就常用的

幾種塗料在英國的海水浪濺區、鹽霧頻繁

出現之處及海水浸沒條件下，提出下列建

議﹕

首次保養期 塗料及

其總額定厚度 (微米)

長 a)鍍鋅 (最低限度85)

(10至20年) 加煤焦油環氧樹脂 (150)

b)煤焦油環氧樹脂 (450)

中 a)鍍鋅 (140)

(5至10年) b)焦油環氧樹脂 (350)

短 a)鍍鋅 (最低限度85)

(不足5年) b)煤焦油環氧樹脂 (250)

104

(less than 5 years) (b)Coal Tar Epoxy (250)

11.9.3 Important Points to Be Considered

The following notes, which are taken partly fromClause 68.1 of BS 6349:Part 1, are particularlyimportant when considering protective systems :

(a) Potential corrosion hazards can be eliminated bycareful design. Reference should be made toAppendix A of BS 5493.

(b) The costs of protective measures are repetitivein that the protective materials themselvesdeteriorate, and regular maintenance andrenewal of coatings will be necessary for allstructures except those with relatively shortdesign lives.

(c) For important, heavily used structures, the needfor regular maintenance and renewal of coatingsshould not be allowed to restrict normal use ofthe structures.

(d) Corrosion does not proceed at a uniform rateover the whole structure or member, and atcertain corrosion points, loss of the originalmaterial can be much more rapid than expected;any estimate of a corrosion allowance is likely tobe excessive for some parts while beinginadequate for others.

(e) The cost of renewing a protective system is likelyto be much more than the initial protection dueto the need to remove marine growth and oldpaint prior to renewal of the system, and the factthat access will usually be more difficult thanduring construction.

(f) Marine growth is prevalent on structures belowmean high water level. Evidence exists that suchgrowth can be protective against corrosion andtherefore generally should not be removed, as itmay be more effective and durable than a paintsystem which might replace it. Normally theonly exposure zones which might usefully be

1 1 . 9 . 3 考慮的要點

在考慮防護系統時，應包括下列幾個

重點（部分選自《B S 6 3 4 9 : P a r t 1》第 6 8 . 1

節）﹕

( a ) 仔細的設計，可消除銹蝕引起的潛

在危險。這方面可參考《B S 5 4 9 3》

附錄A。

( b ) 用於防護措施上的開支，是會不斷

重覆的，因為塗料本身會損壞，除

了設計使用期較短的結構外，所有

結構的塗料均須定期保養和更新。

(c) 對於使用率高且重要的結構，不應

因定期保養和更新塗料而影響其正

常使用。

( d ) 銹蝕不會在整個結構和構件上均速

發展，在某些銹蝕點，材料的損耗

可能比預計的要快得多；任何估算

出的結構銹蝕量，都可能會在一些

部分過高，而在另一些地方不足。

( e ) 更新防護系統的費用，遠比初始防

護高，原因是要事先除掉海洋附殖

物和舊漆；而且工作空間和通道的

限制，通常都比在最初施工時更

多。

( f ) 結構低於平均高潮位的部分，普遍

出現海洋附殖物。有證據顯示，海

洋附殖物可防止銹蝕，並可能比要

代替它的塗料更有效，更耐久，因

而一般不必清除。需要更新塗層的

部分，通常僅限於浪濺區和受大氣

影響的部分。

105

repainted are the splash and atmospheric zones.

11.9.4 Corrosion Protection of Steel TubularPiles

For the corrosion protection of steel tubular piles,covering the immersed, tidal and splash zones, it isunlikely that coal tar epoxy, even when applied with atotal dry film thickness of 400 to 500 µm, will have aneffective life of more than 15 to 20 years, under themost favourable conditions and assuming no damageduring handling and driving. The use of polyethylenesheeting for coating steel tubular piles may beconsidered, and in theory such a system should be ableto offer full corrosion protection for the normalstructure design life of 50 years. The polyethylenesheeting is normally several millimetres thick and isapplied under controlled factory conditions by heat-shrinking on to the outside of the steel tube, which hasbeen treated with undercoat/primer and an adhesivelayer. As for all pile coatings, extreme care is necessarynot to cause damage during handling and driving. Themain disadvantages relate to lack of experience with thematerial amongst local contractors and lack of full scalelong term durability test data under local conditions.

The use of normal site-applied wrappingsconsisting of mastics or primers wrapped withpetroleum jelly impregnated tapes and PVC orpolyethylene outerwraps are generally limited to tierods, pipes and tubular steel piles in the splash zone.Wrapping systems are available for treating tubularsteel piles and other steel members below water level,but these systems are relatively expensive and need onlybe considered for critical repair work where no othersolution is apparent.

For all proprietary coatings and wrappings, wheresite application is unavoidable, the advice of themanufacturer, particularly with regard to surfacepreparation, should be strictly followed and closesupervision maintained.

The electrochemical processes which accompanycorrosion of submerged steel elements in seawater are

1 1 . 9 . 4 鋼管樁的銹蝕防護

對於在水下、水位變動或浪濺區鋼管

樁的銹蝕防護，如果採用煤焦油環氧樹脂

的話，即使總乾膜厚達 4 0 0至 5 0 0微米，

並假設在操作和打樁過程中未受損壞，其

有效使用期在最有利的情況下也多半不

會超過 1 5至 2 0年。可以考慮採用聚乙烯

薄膜，作為鋼管樁保護層。理論上，該系

統可以在一般結構的 5 0 年設計使用期

內，提供全銹蝕防護。聚乙烯薄膜通常厚

數毫米，是在廠房的調控環境下通過熱套

冷縮繞到鋼管上的。在這工序之前，鋼管

須先進行內塗層 /底漆和粘著層處理。正

如其他樁的保護層一樣，在運送和打樁過

程中，必須特別注意，不得讓其損壞。這

個方法的主要缺點，是本地承建商缺少使

用此種材料的經驗，同時，亦缺乏在本地

條件下的長期及全面耐久性試驗數據。

通常，在浪濺區的拉桿、管道及鋼管

樁會採用現場包裹方法。該法利用凡士林

浸漬帶覆蓋瑪 脂或底漆進行包裹，再在

外層加上聚氯乙烯或聚乙烯。也有包裹系

統可以處理水位以下的鋼管樁和其他鋼

構件的，但這些系統費用較高，除非沒有

其他解決方法，而有關維修工作又十分重

要，才會考慮使用。

當使用專利塗料和包裹系統，而須在

現埸施工時，應嚴格遵照生產商的建議，

並加強監管，特別是進行表面處理時，應

更加小心。

《B S 7 3 6 1》 ( B S I , 1 9 9 1 c ) 描述了海水

下鋼構件銹蝕時產生的電化學過程，還詳

述了陰極保護抗銹蝕的方法，其中包括可

耗性電陽極和外接電流系統。一般認為，

陰極防蝕系統的效能，只有在平均潮位以

106

described in BS 7361 (BSI, 1991c), which also givesdetails of the way in which cathodic protection, bothby sacrificial galvanic anodes or by impressed currentsystems, should be applied to combat corrosion.Cathodic protection is usually considered to be fullyeffective up to about half-tide mark. The maindisadvantage of using a cathodic protection system formarine structures covered by this Manual, apart frompossible increased costs compared with other designsand protection methods, relates to a general lack ofexpertise with regard to monitoring work afterinstallation. It is recommended that the detailed designfor any cathodic protection system should be entrustedto a suitably qualified specialist company and anoperating and maintenance manual should beprovided. For monitoring work after installation,consideration should be given to arranging amaintenance contract with a suitably qualified specialist.

下的部分才能充分發揮。在本手冊提及的

海事結構上，應用陰極防蝕系統，其主要

缺點是較其他方法昂貴，另外，安裝後的

專門檢測技術仍然非常缺乏。建議所有陰

極防蝕系統，均應委托有適當資格的專業

公司進行詳細設計，並提供操作和保養手

冊。至於安裝後的檢測工作，應考慮與有

適當資歷的專業人員訂立保養合約。

107

12. TYPES OF STRUCTURE

12.1 General

This Chapter gives guidance on types of structureand includes recommendations on preferred forms ofconstruction and choice of materials whereappropriate. Notes on design criteria are given wherethese have not been covered in other Chapters. Typesof structure covered include breakwaters, seawalls,piers, dolphins, pumphouses, slipways, ramps,navigation aids, outfalls, intakes and miscellaneousminor structures.

12.2 Breakwaters

Information on types of breakwater, withexamples, is given in pages 6-88 to 6-94 of the ShoreProtection Manual (SPM) (CERC, 1984) and Chapter3 of Bruun (1981). Vertical wall breakwaters are rigidstructures; they are generally impermeable and causefull wave reflection, thereby attracting large waveforces and increasing wave activity adjacent to thebreakwater. Main types of vertical wall breakwatersinclude precast concrete blockwork, concrete caissonsand cellular steel sheet piles. Rubble moundbreakwaters have sloping faces and are flexiblestructures; they have significant permeability, are able todissipate wave energy and greatly reduce wavereflection. Outer protective armour is of rock orprecast concrete units. Composite breakwaters consistof a rigid vertical wall construction on a rubble moundfoundation. Depending on the relative depth of thebase of the vertical wall, some wave dissipation usuallyoccurs, resulting in only Partial wave reflection. Wherethe base of the vertical wall is relatively high, problemscan occur with wave scour at the top of the rubblefoundation.

For local conditions, rubble mound breakwatersare normally preferred to vertical wall or compositebreakwaters. Rubble mound breakwaters have thefollowing advantages :

1 2 . 結構類型

1 2 . 1 概述

本章介紹各種結構類型，亦就施工形

式和材料選擇提供建議。在其他章節中未

有提及的設計標準，也會在本章說明。本

章涉及的結構包括防波堤、海堤、碼頭、

船墩、泵房、船排、滑道、助航設備、排

水口、進水口及其他輔助結構。

1 2 . 2 防波堤

《 S h o r e P r o t e c t i o n M a n u a l》 (下稱

《 S P M》 ) ( C E R C , 1 9 8 4 ) 第 6 - 8 8頁至 6 -

9 4頁和B r u u n ( 1 9 8 1 ) 第三章，論述並例

舉了不同類型的防波堤。直立式防波堤是

剛性的結構，一般不透水，波浪會被全面

反射，因此防波堤會承受巨大的波浪力，

也會增強附近的波浪活動。直立式防波堤

的主要類型，包括預製混凝土塊體、混凝

土沉箱和格式鋼板樁結構。堆石防波堤為

斜坡式柔性結構，外層護面為塊石或預製

混凝土塊，其透水性很強，能消耗波能並

大量減少波浪反射。混合式防波堤，是建

立在堆石基床上的剛性直立牆結構。這類

防波堤通常可以消耗波能，使波浪只有局

部被反射，幅度則取決於直立牆底部的相

對深度。若直立牆的底部較高，塊石基床

的頂部會產生波浪 刷問題。

在本地情況下，堆石防波堤一般比直

立式或混合式防波堤優勝。它具有以下優

點：

108

(a) Cost is relatively low due to availability of localrock for core, underlayers and armour, exceptfor the most exposed locations.

(b) Wave conditions are improved due to waveabsorption and minimal reflection, both behindand in front of the breakwater.

(c) Overtopping is easier to control due to greatlyreduced runup compared with vertical wallconstruction.

(d) Damage is progressive and sudden failure isunlikely, due to the flexible form ofconstruction.

(e) Repairs and maintenance can be carried outrelatively easily.

One disadvantage is that floating refuse can betrapped easily in the rubble, and this is environmentallyundesirable.

Guidance on the design of rubble moundbreakwaters is given in Chapter 9. As stated in Section9.4, concrete caps or wave walls should be avoidedwhere possible. Navigation lights should be providedon breakwaters to the requirements of the Director ofMarine. Access steps, in the form of precast concreteblocks, should be provided for light posts down tolow tide level on the protected faces. For typhoonshelters and other similar breakwaters, bollards ormooring eyes may be required by the Director ofMarine to be constructed at locations on the protectedinner faces.

Innovative designs may be required whereconventional breakwater design would result inunacceptable reduction of water quality due toobstruction of currents.

12.3 Seawalls

It is important to distinguish between seawallswhose only function is to protect the adjacent land

( a ) 除非防波堤位於非常開敞的水域，

否則，堤心、墊層和護面石料在本

地都有供應，因而建造費用較低。

( b ) 具有較佳的波浪吸收性能，反射很

小，所以波浪狀況會得到改善。

(c) 與直立式結構相比，波浪上衝量較

小，因而較易控制越堤浪。

( d ) 由於其結構屬柔性，損壞是漸進式

的，因而不會突然塌毀。

( e ) 維修與保養，相對地容易進行。

其缺點是，漂浮的垃圾容易被截留在

塊石之間，影響環境。

第九章提供了設計堆石防波堤的指

引。按第 9 . 4節所述，應盡量避免使用混

凝土護頂或混凝土防波牆。按海事處的要

求，須在防波堤上，設置航行燈標，並應

在防波堤受保護一方加設以混凝土預製

塊建成的梯階，以便從低潮水位通往堤面

的燈標。對避風塘和其他類似的防波堤，

海事處可能會要求在防波堤的內側，設置

繫船柱和繫船環。

若採用傳統的防波堤設計會令水流受

阻，引致水質下降時，應考慮一些特殊的

設計。

1 2 . 3 海堤

要留心區別兩種不同類型的海堤，一

種專為防止附近陸地被海水 蝕；另一種

109

from erosion by the sea, and seawalls which, inaddition, have a secondary, and sometimes major,function of providing a berth for vessels. The term'seawall' should strictly only be applied to the first type,where no berthing is possible or allowed for, and theterm 'quay wall' should be used where berthing ispossible or a primary requirement. Details of types ofseawall are given in pages 6-1 to 6-14 of the SPM. Thestructure may be rigid, flexible or of some intermediatetype, the choice of type being heavily dependent on thedegree of exposure of the site to wave attack.

For local conditions, seawalls of rubble moundconstruction are preferred. Similar advantages overrigid impermeable structures apply as given in Section12.2 for rubble mound breakwaters. Guidance ondesign is given in Chapter 9; comments on concretecaps and wave walls are given in Section 9.4. Thestructure will be permeable and flexible, and anyhandrail and pavement edge should be set well backfrom the seawall crest to minimise maintenanceproblems.

Details of various types of quay wall, withexamples, are given in Chapter 4 of Bruun (1981).Quay walls can be divided into two main types : sheetwalls and gravity walls. Types of sheet wall structureand sheet wall are given in Sections 4.3 and 4.4 ofBS 6349:Part 2 (BSI, 1988). Types of gravity wallare given in Section 5.2 of BS 6349:Part 2.

In cases where excavation of soft material from theseabed is not practicable, alternative foundationdesigns, for example employing in-situ strengthening ofsoft material should be considered.

For local conditions, with required water depthalongside not exceeding about 7 metres, gravity quaywalls of concrete block construction, using standardconcrete blocks and standard seawall sections whereappropriate, are preferred. Such concrete block quaywalls have the following advantages :

(a) Cost is relatively low due to experience of localcontractors with this type of construction and

除有上述功能外，還為船舶提供靠泊地

方。嚴格地說，「海堤」一詞是指第一類，

不能或不容許用作靠泊用途的結構。「裝

卸堤」一詞則應用於容許靠泊，甚至是其

主要功能的結構。《 S P M》第 6 - 1至 6 - 1 4

頁詳細地論述了海堤的類型。海堤結構可

為剛性、柔性或混合型，選擇時主要取決

於現場的波浪情況。

在本港，採用堆石結構式的海堤較為

適合，它比剛性不透水式結構優勝的地

方，與第 1 2 . 2節所述有關堆石防波堤相

似。第九章列出了海堤的設計指引；第 9 . 4

節論述了海堤的混凝土護頂和防波牆。由

於堆石海堤是透水性高的柔性結構，任何

欄桿和鋪面邊緣，均應遠離海堤堤頂，以

減少維修困難。

B r u u n ( 1 9 8 1 ) 第四章論述並例舉了各

種裝卸堤的類型。它主要分為兩大類：板

樁堤和重力式堤。《B S 6 3 4 9 : P a r t 2》( B S I ,

1 9 8 8 ) 第 4 . 3節和 4 . 4節列出了板樁堤的結

構 及 其 類 型。 重 力 式 堤 的 類 型 則 在

《B S 6 3 4 9 : P a r t 2》第 5 . 2節中列出。

若不能開挖海床的軟土，應考慮採用

其他地基設計方式，例如現場軟基加固方

法。

在本港，如果沿岸所需水深不超過 7

米，建議採用以混凝土方塊建造的重力式

裝卸堤，若情況許可，可以採用標準的混

凝土塊體和海堤剖面設計。此類裝卸堤具

有下列優點：

( a ) 對於這種工程，本地承建商具有豐

富的經驗，能有效使用材料，因此

110

efficient use of materials.

(b) The form of construction has a long history ofsatisfactory performance with negligible needfor maintenance.

(c) The construction has some flexibility and cancope with some differential foundationsettlement without risk of sudden failure.

(d) Modification work is relatively simple, anddamage from vessels in accidents is usuallyminor.

(e) Incorporation of landings, pumphouses anddrainage outfalls into lengths of wall is relativelysimple.

(f) The form of construction can be used for alarge range of sea bed depths and subsoilconditions by varying the dredging depth andextent of rubble foundation to suit.

Disadvantages of concrete block quay walls relatemainly to the relatively long construction periodrequired and the need for a large casting yard andstacking area with marine frontage; however, thesedisadvantages can generally be reduced in significancewith adequate project planning. Another disadvantageis that vertical walls reflect waves, with the consequencethat adjacent wave activity is increased.

It should be noted that standard quay wall sections(CED, 1991) with toe levels at approximately +0.30,-1.05, -2.40, -3.75, -5.05 and -6.40 mCDincorporating standard concrete blocks are suitableonly for use in relatively protected locations notexposed to severe waves, where the required groundlevel is approximately +4.0 mCD and the required liveload behind the seawall is limited to 10 kPa. For otherlocations, ground levels and loadings, it may still bepossible to use the standard sections, but the designmust be checked in detail. Where checks show that thestandard sections are not satisfactory, factors of safetyagainst sliding and overturning can be improved by :

費用較低。

( b ) 這種建造形式具有長期的良好紀

錄，幾乎無須保養。

(c) 此類柔性結構，能抵受一定程度的

不均勻地基沉降，不會突然倒塌。

( d ) 改建工作較為簡單，船隻造成的意

外損壞較小。

( e ) 在堤身加建登岸台階，泵房和排水

口比較容易。

( f ) 通過調整挖泥的深度和塊石地基的

大小，此類結構適用於差距甚大的

水深和地基條件。

混凝土方塊裝卸堤的缺點，主要是施

工期較長，及須在臨海地區建立大面積的

澆注場地和堆置場，但只要計劃安排適

當，便可減少這些缺點的影響。它的另一

缺點，是直立牆會反射波浪，加劇附近的

波浪活動。

標準裝卸堤剖面設計 ( C E D , 1 9 9 1 ) 採

用了標準混凝土方塊 ，其堤腳高程為

+ 0 . 3 0、- 1 . 0 5、- 2 . 4 0、- 3 . 7 5、- 5 . 0 5和 - 6 . 4 0

m C D，應該注意的是，這些設計只適用

於沒有大浪襲擊的有屏障水域，地面高程

約為 + 4 . 0 m C D，並且堤後的活荷載不

超過 1 0 k P a。這些標準剖面設計也可用於

其他位置、地面高程和荷載條件，但須經

詳細驗核。如果發覺標準剖面設計不符合

要求，可通過以下方法提高抗滑和抗傾覆

的安全系數：

111

(a) incorporating keys at horizontal joints,

(b) widening of the section at critical levels, and

(c) improving the quality of the fill normally placedimmediately behind the seawall.

For all concrete block quay walls, whether standardsections are used or not, care should be taken to checkthe stability of the bermstones and adjacent rubblefoundation against possible scour and underminingfrom wave attack; this is particularly important forwalls with shallow toe levels in exposed locations.

Toe levels of concrete block quay walls should bedetermined following consultation with the Directorof Marine, who will also advise on locations of publiclandings, bollards, mooring eyes and ladders. It isnormal to provide standard timber fendering systemsfor public landings, but for public water fronts andpublic cargo working areas, fenders need not beprovided. Mooring eyes, ladders and handrails shouldpreferably be of stainless steel, particularly wherelocated within the tidal, splash or spray zones. Noticeboards should be provided as required by the Directorof Marine.

12.4 Piers

12.4.1 General

Details of types of piers, with examples, are given inChapter 4 of Bruun (1981). The majority of piers aresuspended deck structures; examples of types ofsuspended deck structure are given in Section 6.4,Table 1 and Figure 41 of BS 6349:Part 2. Figure 44of BS 6349:Part 2 gives examples of structuralarrangements used to resist berthing loads, andFigure 45 gives examples of pile and deckconnections.

For local conditions, preference is for reinforced orprestressed concrete suspended decks, with maximumuse of precasting for individual members, andprestressed concrete piles or steel tubular piles, infilled

( a ) 在水平接縫加鍵，

( b ) 在關鍵性高程加寬剖面，及

(c) 在海堤後方 ，選用較優質的回填

料。

所有混凝土方塊裝卸堤，無論是否採

用標準剖面設計，均應注意護腳石和相鄰

堆石基床在波浪的侵蝕和淘空作用下的

穩定性，對處於無屏障水域，及坡腳較淺

的岸堤，這尤為重要。

混凝土方塊裝卸堤的堤腳高程，應與

海事處商議確定，海事處亦會提供公用登

岸台階、欄桿、繫船柱和繫船環的位置。

登岸台階一般應設有標準的護木系統，但

公眾堤岸和公眾貨物起卸區則毋須配備

護木。繫船環、爬梯和欄桿，應盡量採用

不銹鋼材料，特別是在潮位變動、浪濺和

浪花區，更有必要。告示牌應按海事處的

要求配置。

1 2 . 4 碼頭

1 2 . 4 . 1 概述

B r u u n ( 1 9 8 1 ) 第四章詳述了不同的碼

頭類型，並提供了一些例子。大部分碼頭

均為承台式結構；在這方面《 B S 6 3 4 9 :

Par t 2》 第 6 . 4節、表 1和圖 4 1提供了一些

範例。《B S 6 3 4 9 : P a r t 2》圖 4 4例舉了承

受靠泊荷載的結構的佈置方式，圖 4 5則提

供了樁柱和面板接合的例子。

在本港，提議採用鋼筋混凝土或預應

力鋼筋混凝土承台結構；構件應盡量預

製，並採用預應力鋼筋混凝土樁或鋼管

樁，鋼管樁內要填以鋼筋混凝土直至海床

以下；在海床以上的鋼管，可視為非結構

112

with reinforced concrete to below seabed level, withthe steel casing above seabed level being treated asnon-structural. The advantages of such constructionrelate mainly to minimising maintenance costs.

For comments on standards for ferry piers and thesiting of ferry piers, see Volume 9 of the TransportPlanning & Design Manual (Transport Department,1986). Vessel design requirements and layoutrequirements for ferry piers and public piers should beagreed with the Commissioner for Transport, theDirector of Marine, and the proposed ferry operatorsas appropriate. For public piers, it is suggested that thepier structure and fendering system should be designedfor use by vessels up to about 400 t displacement; thiswill allow for possible use by existing double deckferries in an emergency.

12.4.2 Public Piers

Timber fenders at about 0.6 to 0.9 m centres, withtimber walings and cylindrical rubber end-on buffers,are considered most appropriate for use for publicpiers, because of the need to cater for a large range ofvessel size. Sets of landing steps, preferably 2 m wide,should be provided at minimum 30 to 40 m centres;each set should have two landings, each 1.5 to 2.0metres long, at approximate levels of +2.5 and+1.0 mCD. Fenders should extend from about+0.3 mCD to at least +3.8 mCD. These levels areapplicable to tidal conditions in Victoria Harbour. Atlocations which have different tidal ranges, these levelsshould be reviewed. A top capping piece should beprovided to prevent fouling by ropes, and timber stepblocks provided at the landing steps. Standard 10 tbollards at about 8 to 10 m centres are consideredappropriate, with a reasonable number of mooringeyes or cleats at each set of landing steps. Handrails,preferably of stainless steel, should be provided atlanding steps. Navigation lights should be provided tothe requirements of the Director of Marine.

性的部件。此結構的優點，主要是維修費

用較低。

關於渡輪碼頭的標準和選址的討論，

可參閱《T r a n s p o r t P l a n n i n g & D e s i g n

M a n u a l》( T r a n s p o r t D e p a r t m e n t , 1 9 8 6 )

第九卷。渡輪和公用碼頭的船型設計，和

平面佈置要求，應按情況與運輸署、海事

處及有關渡輪公司商議確定。至於公用碼

頭方面，建議其結構和護舷系統的設計，

應適合排水量達 4 0 0公噸的船舶，以便現

有的雙層渡輪在應急時也可使用。

1 2 . 4 . 2 公用碼頭

至於公用碼頭，為滿足大小不同船舶

的需要，可按 0 . 6至 0 . 9米的間距佈置護

木，再加上橫向護木和邊壓圓形橡膠護

舷。登岸台階應寬 2米，每組中心距 3 0至

4 0米，而每組有兩個平台，各長1 . 5至 2 . 0

米，高程大約在 + 2 . 5和 + 1 . 0 m C D。護

舷裝置應從 + 0 . 3 m C D至少延伸到 + 3 . 8

m C D。上述的高程適用於維多利亞港的

潮汐情況。在有不同潮差的地區，應重新

審訂。為防止被繩索拖損，應在頂部配備

壓簷木，並在登岸台階上安裝踏木塊。每

隔 8至 1 0米處，應設一個1 0公噸的標準繫

船柱，並在每組登岸台階上都適當地備有

若干繫船環和繫繩鐵角。登岸台階還須配

備欄桿，以不銹鋼材料製造為佳。航標燈

要按海事處的要求配置。

113

12.4.3 Ferry Piers

Fendering systems for ferry piers should bedesigned on an individual basis to suit the expectedvessel use, after consultation with the proposed ferryoperator, as the operator will generally be responsiblefor maintenance of the fendering system under theterms of his franchise or licence. Locations of bollardsand other fixtures and fittings should be decided in asimilar manner after consultation with the proposedferry operator.

For ferry piers and single user piers where vesselshave berthing or rubbing strips, and the range of vesselsize using each pier is restricted, although a timberfendering system may still prove to be satisfactory,consideration should be given to providing other typesof fendering system, which may be more cost effectivein the long term. One such suitable type of systemconsists of steel frontal frames with nylon orpolyethylene wearing pads supported on rubber cellfenders. The main advantages of such a system are :

(a) The deflection/energy/reaction characteristicsare such that relatively constant low reactionswill apply for a range of energy absorption.

(b) For relatively light, thin hulled vessels such ashydrofoils, the reaction on the vessel berthing orrubbing strips can be kept within acceptablelimits by selecting suitably wide frontal frames.

(c) The lengths of the frontal frames can be selectedto cover the full required tidal range.

(d) By rotating the nylon or polyethylene wearingpads, even wear rates can be maintained andefficient use made of the pads. This is notpossible with timber fenders, where materialwear is concentrated. Comments on the use offender piles are given in Section 11.8. Particularattention should be paid to the possible need toreplace fender piles during the design life of thepier.

1 2 . 4 . 3 渡輪碼頭

渡輪碼頭的護舷系統，應該根據預計

的船舶使用情況進行設計，並應與有關的

渡輪公司商議，因為在專營協議或牌照

中，通常都會要求該等公司負責保養護舷

系統。繫船柱及其他附屬設備和配件的安

裝位置，同樣應與渡輪公司商議確定。

在一些渡輪碼頭或專用碼頭，靠泊的

船隻都有靠泊或摩擦邊條裝置，而大小也

受到限制，在此情況下，儘管護木護舷系

統的效果可能令人滿意，仍應考慮使用其

他形式的防撞裝置，長期使用的話，它們

可能更具經濟效益。其中一種是由支承在

鼓形橡膠護舷上的防撞鋼構架組成，並在

表面安裝有尼龍或聚乙烯耐磨墊。其主要

優點是：

( a ) 由於在一定的能量吸收範圍內，其

變形 /能量 /反力特性，產生的反力

會相對地穩定及細小。

( b ) 在水翼船等船體較輕、殼較薄的船

上，可選擇較寬的防撞鋼構架，使

在靠泊或摩擦邊條上的反作用力，

能保持在容許的範圍內。

(c) 防撞鋼構架的長度，可按潮差幅度

選定。

( d ) 通過轉動尼龍和聚乙烯耐磨墊，可

以使其磨損較平均，而且更符合經

濟原則。護木系統的磨損非常集

中，因而不可作同樣的處理。第 1 1 . 8

節論述了護舷樁的使用，應特別注

意的是，護舷樁可能須在碼頭的設

計使用期內更換。

114

12.5 Dolphins

Useful general comments on dolphins andexamples of different types of flexible and rigidstructures are given in Section 7 of BS 6349:Part 2.The comments given in Section 12.4 regardingpreferred materials for construction of piers applyequally to dolphins. Fenders should be provided formooring dolphins because of the possibility ofaccidental vessel impact. Fendering systems for bothberthing (breasting) dolphins and mooring dolphinsshould be simple and robust, with the aim ofminimising future maintenance. The Director ofMarine should be consulted on the need for navigationlights on tops of dolphins.

12.6 Pumphouses

12.6.1 General

Pumphouses covered by this Manual include sets ofindividual small units, interconnected small units andlarger units for installation of pumps for providing saltwater for buildings, usually for air-conditioningpurposes.

12.6.2 Layout and Location

In the design and construction of pumphousescovered by this Manual, the requirements of the clientfor such details as size, layout, facilities and fittingsshould be provided by or agreed in advance with theclient. The following points should be noted whenselecting a site for a pumphouse :

(a) The intake should be remote from sewageoutfalls and other sources of contamination anddebris, and also from salt water outlets whichdischarge heated water.

(b) The seabed should be sufficiently deep toaccommodate the intake, after allowance forsilting.

(c) The water in front of the intake should not be

1 2 . 5 船墩

《B S 6 3 4 9 : P a r t 2》 第 7節載有關於船

墩的一般論述，並例舉了不同類型的柔性

和剛性結構。第 1 2 . 4節所述的碼頭結構的

優選材料，同樣也適用於船墩。因有船舶

意外碰撞的可能，繫船墩應裝有護舷系

統。靠船墩和繫船墩的護舷系統，均應簡

單、堅固，以減少將來所需的維修工作。

至於是否須在船墩頂部設置導航燈，應諮

詢海事處。

1 2 . 6 泵房

1 2 . 6 . 1 概述

本手冊涉及的泵房設計，包括獨立小

單元的組合、互相連接的小單元，以及大

型的單元，安裝水泵後可為建築物供應鹹

水，而主要用於其空氣調節系統內。

1 2 . 6 . 2 平面佈置和定位

在設計和建造這些泵房之前，應與委

托人商訂詳細的技術細則，例如尺度、佈

置、設備和配件等要求。選址時，應注意

以下幾點：

( a ) 進水口應遠離污水排放口及其他污

染物和廢料的來源，亦應遠離加熱

後鹹水的排放口。

( b ) 在將泥沙的沉積計算在內之後，進

水口處的海床仍有足夠的深度。

(c) 進水口處的海水應保持流動，與其

相鄰海堤則不得靠船。

115

stagnant and the adjacent seawall should not beused by vessels for berthing.

12.6.3 Structure and Design

Pumphouses normally consist of reinforcedconcrete units, precast where placed below generalwater level and cast in situ above water level. To ensurethat the units are watertight, it is recommended that thedesign of all walls and base slabs in contact withseawater should be in accordance with BS 8007 (BSI,1987).

Pumphouse units are usually constructed as Part ofa concrete blockwork quay wall founded on concreteblocks or on an extended rubble seawall foundation.To avoid possible future settlement problems, it isimportant that the underlying ground is consolidatedby preloading before the setting of the pumphouseunits. This preloading is particularly important where apumphouse is to be constructed as an extension to, orimmediately behind, an existing quay wall. Thepumphouse units are connected to the sea by intakesformed in special precast concrete blocks. To ensuresatisfactory operation of the pumps in all tidal andwave conditions, it is recommended that the crown ofthe intake should generally be at a level not higher than-0.6 mCD, see Section 12.9.

For ease of construction and to minimise thenumber of joints, precast pumphouse units should beindividual self-contained units with walls formed to ashigh a level as possible, subject to weight limitations,and preferably to a level between MSL (+1.4 mCD)and MHHW (+2.1 mCD) for harbour locations. Forlarger pumphouses, sets of units can be interconnectedabove the junction between the precast and in situconcrete level. It is usual for precast pumphouse unitsto be cast on a waterfront site, lifted by crane or cranebarge, transported to the pumphouse site by barge,and set in position by crane or crane barge. For thismethod of construction, the weight of an individualunit is limited by the lifting capacity of available plant;units within the weight range of 50 to 100 t arerelatively common. Another method of construction is

1 2 . 6 . 3 結構和設計

泵房一般由鋼筋混凝土構件組成，通

常水位以下部分會預製，水位以上部分則

現澆。為確保各構件不會透水，與海水接

觸 的 牆 和 底 板 ， 均 應 按 《 B S 8 0 0 7 》

( B S I , 1 9 8 7 ) 設計。

泵房構件通常建於混凝土方塊或延伸

的堆石基床上，作為混凝土方塊裝卸堤的

一部分。為避免將來可能有沉降問題，在

放置泵房構件之前，應先預加荷載，使地

基固結。如果泵房是建於原有裝卸堤後或

作為其延伸部分，預加荷載尤為重要。泵

房的進水口由預製混凝土塊體構成。為確

保水泵在任何的潮汐和波浪條件下均能

良好運作，進水口頂部高程不應超過 - 0 . 6

m C D，詳情可參閱第 1 2 . 9節。

為便於施工和減少接縫數量，各預製

泵房構件應為獨立的單元，在不超越重量

限制的情況下，單元的牆壁要盡量加高，

如果在港內，建議其頂部應在平均海平面

( + 1 . 4 m C D ) 和 平 均 高 高 潮 位 ( + 2 . 1

m C D ) 之間。對於較大的泵房，各構件可

在牆壁的預製和現澆混凝土接合處以上

相接。預製泵房構件，通常在臨海澆注場

製造，用起重機或浮吊起吊，由躉船運至

泵房工地，再由起重機或浮吊安放。應用

此種施工方法時，各構件重量受到起重設

備的限制；構件重量在 5 0 至 1 0 0公噸範

圍內較為普遍。另一種施工方法是在澆注

構件後，利用滑道下水，將之漂浮及牽引

到泵房工地，再用起重機或浮吊安放就

位。

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for the unit to be launched on a slipway after casting,floated, towed to the pumphouse site and set inposition by crane or crane barge.

When using the construction method referred toabove, involving transport by barge, it is usual to testeach unit at the casting yard for watertightness by fillingthe unit with water and leaving it filled for at least 24hours. Although this method of testing does not fairlyreflect normal water pressures during pumphouseoperation, it is far simpler and less expensive thanimmersing the unit in water. Whichever method oftesting is adopted, it is important that, during the designstage, the test loading condition is also checked and thereinforcement designed and detailed accordingly.Water or sand is usually used as ballast during theplacing of the precast pumphouse units to guardagainst buoyancy. Such ballast should not be removeduntil a careful design check is made on the buoyancy ofthe structure.

12.6.4 Ties and Waterstops

When drafting Particular Specification clauses, itshould be noted that BS 8007 recommends that tiesused to secure and align formwork should not passcompletely through any liquid-retaining Part of thestructure, unless effective precautions can be taken toensure watertightness after their removal. The ends ofany embedded ties should have cover equal to thatrequired for the reinforcement. The gap left from theend of the tie to the face of the concrete should beeffectively sealed. Although it has been commonpractice to provide central waterstops and keys atconstruction joints between the precast units and in situconcrete sections, BS 8007 states that waterstops arenot usually required for construction joints withcomplete continuity in water-retaining structures and, inAppendix D of BS 8007, an example of aconstruction joint with no waterstop or key is shown.Central waterstops can be difficult to fix and hold inposition during concreting, and problems can beexperienced when placing and compacting concretearound the waterstop. As explained in BS 8007,

使用上述利用躉船載運的施工方法

時，一般會在澆注場進行防水試驗，方法

是將水灌入各構件，保持至少2 4小時。雖

然此種試驗方法不能準確地模擬泵房運

作期間的正常水壓，但比把構件沉入水中

試驗要簡單和經濟得多。無論採用那種試

驗方法，在設計階段都應檢核試驗荷載條

件，並相應地設計與佈筋。安放預製泵房

構件時，通常會用水和沙作為壓重物以對

衡浮力。須仔細驗核浮力設計後，方可卸

掉壓重物。

1 2 . 6 . 4 拉桿和止水塞

在擬定特別規格條款時，應該注意的

是，《B S 8 0 0 7》的有關建議，除非利用

有效的預防措施，確保拉桿除掉後結構仍

不透水，否則用來固緊和定位模板的拉桿

不應完全穿過結構的擋水部分。埋置式拉

桿的末端，都應有保護層，其厚度與保護

鋼筋所需的相同，而拉桿末端與混凝土表

面之間的缺口須有效地密封。儘管預製件

和現澆部分之間的施工縫，通常會加上中

置的止水塞和鍵，但《B S 8 0 0 7》仍指出，

擋水結構中的施工縫，如果具有完整的連

續 性 ， 一 般 可 以 不 須 使 用 止 水 塞 ，

《B S 8 0 0 7》附錄D舉出了一個不帶止水

塞和鍵的實例。在澆注混凝土過程中，安

裝和固定中置止水塞，及在止水塞周圍澆

注 和 搗 實 混 凝 土 都 比 較 困 難 。 如

《B S 8 0 0 7》所述，無論是否使用止水塞，

在泵房牆壁上的施工縫進行表面處理

時，都應特別小心。

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whether or not a centre waterstop is used, extreme careshould be taken during surface preparation forconstruction joints in pumphouse unit walls.

12.6.5 Screens, Guides and Fittings

Pumphouse intake screen guides may be stainlesssteel or cast iron sections bolted onto the outside of theconcrete intake blocks, or formed directly as a recess inthe concrete intake blocks themselves. For the formercase, the guides should be protected from damage byvessel impact using securely fixed timber fenders. Forthe latter case, the concrete nib between the recess andthe outer block face should be detailed with care, withstainless steel sections being used as necessary to protectand line the recess. Problems have been experiencedwith such nibs due to inadequate thickness and concretecover, combined with inappropriate reinforcementdetailing.

Screens may be of stainless steel, PVC tubing,hardwood, or a combination of materials as specifiedby, or agreed with, the client. For sets of pumphouseunits constructed for possible future use by Partiesother than the client, it is suggested that fabrication ofthe screens should be made the responsibility of theeventual users. The time between construction of thepumphouse and handover can often be several years; ifthe screens are placed in the guides immediately afterconstruction, later removal will be difficult due tomarine growth, and the alternative of storage for anindefinite period is not efficient or appropriate.

Internal and external steel fittings and fixtures, suchas ladders, gratings, guide covers and runway beams,should be stainless, galvanised or painted with coal tarepoxy, as agreed with the user. To protect the internalfittings and to guard against the entry of silt and otherdeposits, a temporary stopper should be provided toblock the intake pipe.

1 2 . 6 . 5 攔污柵、導框和配件

泵房進水口攔污柵導框，可用不銹鋼

或鑄鐵製造，用螺栓固緊到進水口混凝土

塊體上，或直接在進水口混凝土塊體上鑄

成凹縫。若用第一種設計，導框應安裝護

木，以防船舶碰撞造成損壞。若用第二種

設計，則須小心詳細設計凹縫和塊體表面

之間的混凝土突邊，需要時可使用不銹鋼

型材保護和加固凹縫。以往這些凹縫出現

過很多問題，主要是由於混凝土和保護層

厚度不足，加上佈筋不當而引起。

按委托人要求或經委托人同意，可用

不銹鋼、聚氯乙烯管、硬木或混合材料製

造攔污柵。如果泵房將來的使用者並非當

時的委托人，建議攔污柵應由該使用者安

裝，由於泵房從施工到交付使用，往往需

要幾年時間，如果在竣工後，立即將攔污

柵放到導框裏，因海洋附殖物的累積，將

來移去時會很困難，而長期儲存這些導框

也不適當。

諸如爬梯、格柵、導框蓋和軌道橫樑

等內、外部鋼配件和附屬裝置，均應得到

使用者同意，方可確定用不銹鋼、鍍鋅

鋼，或塗上煤焦油環氧樹脂的鋼材製造。

完成後的進水管，須用臨時塞堵住，以保

護內部配件，並防止泥沙或其他沉積物進

入。

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12.7 Slipways And Ramps

12.7.1 General

A slipway is a structure, consisting of a rail track,cradle and haulage device, used in ship building andship repair work for the movement of vessels to andfrom the sea. The cradle is used to support the vesseland runs along the rail track, usually of standard flat-bottomed rails in two, three or four parallel lengths.Wire ropes are usually used to haul the vessel by meansof a winch. Useful information on slipways is given byGrove & Little (1951).

12.7.2 Location and Basic Dimensions

Slipways should be located, where possible, at siteswell protected from wave action. The slipwaydimensions will depend on the size of the largest vesselto be slipped; in general the length of track above highwater should exceed the vessel length, and the lowerend of the track should extend to a depth adequate toallow the cradle to clear the vessel at lowest tide. Theoverall slipway width should be at least one and a halftimes the width of the largest vessel, and the gradient ofthe track within the range 1 in 10 to 1 in 25, with about1 in 15 being normal.

12.7.3 Slipway Design

To a large extent, slipway design will depend on themethod of construction; construction in the dry withina cofferdam may be more expensive in terms of initialcost than construction underwater, but will enablebetter quality of construction and tighter tolerances,resulting in a significant reduction in likely long termmaintenance costs. With piled foundations, differentialsettlement will be controlled. With rubble moundfoundations, it is essential that pre-loading is carried outto limit future differential settlement. Track support

1 2 . 7 船排和滑道

1 2 . 7 . 1 概述

船排是包括軌道、承船架和牽引設備

的結構，在造船和修船時用來拖帶船隻上

水及下水。承船架的用途是支承船隻沿軌

道滑行。軌道一般有二、三或四條並列的

標準平底鋼軌。船隻牽引則常利用絞車和

鋼纜進行。G r o v e & L i t t l e ( 1 9 5 1 )載述了

船排的資料。

1 2 . 7 . 2 定位和基本尺度

船排應盡量設置在免受波浪影響的地

方。船排尺度按將會處理的最大船舶尺度

而定；高潮位以上的軌道長度應超過船

長，軌道下端應伸至足夠的深度，使承船

架能在最低潮時，讓船舶離開。船排總寬

度至少應為最大船寬的 1 . 5倍；軌道坡度

範圍從 1 : 1 0到 1 : 2 5，而 1 : 1 5的坡度較為常

見。

1 2 . 7 . 3 船排設計

船排設計很大程度上取決於施工方

法。在圍堰內進行乾地施工，價格比在水

下施工高，但能達致較好的施工質量，誤

差較小，使長期保養費用顯著地減少。船

排如採用樁柱地基，便可以減低不均勻沉

降。如採用堆石地基，則必須施用預加荷

載，以減低將來的不均勻沉降。軌道支承

樑，須用橫向拉桿連接，以保持軌距。軌

道安裝設計，應該顧及在船排的設計使用

期內須進行重新整平和調向，以及更換因

銹蝕而損壞的上截鋼軌的要求。軌道通常

119

beams should be connected by cross-ties to maintaintrack gauge. Rail track fixing details should allow forpossible relevelling and realignment during the designlife of the structure, and also possible replacement ofthe upper lengths due to corrosion; it is common forthe track to be laid on a hardwood timber runner andfixed in position using special track spikes at the edgesof the rail bottom flange. Setting tolerances for lineand level will depend on the cradle design, but willnormally be significantly tighter than for general marineworks, and Particular Specification clauses should bedrafted to reflect this; a tolerance of ± 10mm for lineand level is considered typical, but is often difficult toachieve for underwater work.

For the design of the rail track support beams, themain problem relates to the assessment of the loaddistribution as the vessel ceases to be waterborne andbecomes carried on the loading cradle. At the start ofslipping, with the cradle at the bottom of the slipway,the vessel is warped into position until bearing isobtained on the first section of the cradle. As slippingcommences, by hauling up the cradle, gradually moreand more weight is taken by the first section, and thisload reaches the maximum just as the second sectionbegins to take a share of the weight. Thereafter, allsections progressively take some load until the vessel isclear of the water and bearing uniformly over thewhole cradle length. The exact value of the maximumload bearing on the first section, or 'sue' load, dependson the draft and outline of the vessel concerned, but asa guide can be taken to be about one third of the vesselweight. Since the sue load is only effective over arelatively short length, it is unnecessary to design the fullslipway length for this load. The lowest length needonly be designed to carry the weight of the cradle, andthe upper length to carry the weight of the cradle plusvessel uniformly distributed. The intermediate lengthshould be designed for the full sue load, or aproportion of the full sue load increasing from thelower end to the full sue load at the upper end, asappropriate.

Care should be taken in estimating the crossdistribution of load; with a cradle carried on two railsonly, it is safe to regard the load as being equallydivided between them, but where three or four rails are

會置於硬木軌枕上，並在軌底翼緣處，用

專門道釘固定就位。固定時，整平調向的

容許誤差，按承船架的設計而定，但通常

比一般海事工程的容許誤差小得多，因

此，應該擬定一特別規格條款加以說明；

常用的整平、調向容許誤差為 ± 1 0 毫

米，水下施工卻往往難以達到要求。

鋼軌支承樑設計的重點，是當船隻剛

停止漂浮，座落在承船架上時，荷載分佈

的估算。滑動開始時，承船架在船排底

部，船舶會被絞到適當位置，並支承在承

船架的第一段。開始滑動後，承船架被牽

引向上，它的第一節所承受的重量逐漸加

大，當第二節剛開始承重時，第一段便受

到最大荷載。隨後，各節逐漸承受一部分

荷載，直至船舶離開水面，使整個承船架

均勻地承重。第一節所承受的實際最大荷

載值，或稱「起承」荷載，取決於有關船

舶的吃水和外形，建議可取船重的三分之

一值。因為起承荷載只作用在較短的長度

上，所以不須整個船排都按此荷載設計。

在最低段只須按承船架的重量設計，而最

高段則須承受承船架的重量及均勻分配

的船舶重量。中間段應按起承荷載設計，

或按情況在下端只採用部分起承荷載

值，逐漸加大，到上端時採用十足起承荷

載值。

應小心估算橫向荷載分佈。只有兩條

軌道支承承船架時，可把荷載平均分配到

該兩條軌道上；如果有三或四條軌道，則

這假設便不成立，因軌道可能經歷沉降而

導致承船架負載不均勻，建議在這情況

120

involved, such an assumption is not recommended dueto possible rail settlement causing the cradle to carryloads unevenly, and it is recommended that each railshould be designed for at least one half of the load.

12.7.4 Ramp Design

In comparison with a slipway, a ramp is a relativelysimple structure. It consists essentially of a concreteslab sloping from about lowest tide level to above hightide level, for the movement of vehicles, usually fromvessels to the shore. Design criteria should be agreedwith the client. Design axle loads are typically 5 to 10 twith a maximum of about 12 t, with a normal rampwidth of about 8 m and a slope of about 1 in 12.

A simple rubble foundation, at least 3 m thick, isusually satisfactory for a ramp, as settlement problemsare not usually significant. The section within the lowertidal range is usually constructed using precast concreteblocks, for ease of construction and additional stabilityfrom possible wave scour and vessel underside/rampfouling. The upper section is usually a normal in situconcrete slab, typically 0.3 m thick, either reinforcedfor crack control or unreinforced with joints at 4 to5 m centres. Care should be taken to ensure that therubble foundation at the lower end and sides istrimmed, and checked by a diver, to ensure noprojection of rubble above the slab line which mightcause damage to a vessel approaching the ramp.

12.8 Navigation Aids

Aids to navigation are used to mark limits ofstructures such as piers, quay walls, breakwaters anddolphins, channel entrances, boundaries and turns, andhidden dangers such as shoals and rock outcrops, to actas a guide for vessels and to assist with their safemovement. The type, size, location and details offittings and fixtures for navigation aids should be to therequirements of the Director of Marine.

下，每條軌道至少按總荷載的一半設計。

1 2 . 7 . 4 滑道設計

與船排相比，滑道是一種較簡單的結

構，它主要包括一個從最低潮位到高潮位

以上的傾斜混凝土板，供車輛登岸或登船

之用。設計標準應與委托人商議確定。設

計軸壓一般為 5至 1 0公噸，最大約 1 2公

噸。標準滑道寬約 8米，坡度為 1 : 1 2。

因為沉降一般不很嚴重，滑道應用簡

單的塊石基床，厚度超過 3米，通常便已

經足夠。在低潮位以下的那段，通常會用

預製混凝土塊體建造，因其施工簡便，當

遇到波浪 刷及船底和滑道之間發生碰

撞時，亦可提供額外穩定作用。滑道的上

段，一般是厚 0 . 3米的現澆混凝土板，可

以是鋼筋混凝土以控制裂縫，也可採用有

間距 4至 5米的接縫的無配筋混凝土。滑道

下端和兩側的塊石應盡量修齊，經潛水員

檢驗，確保混凝土板上無石塊突出，以免

對準備進入滑道的船舶造成損壞。

1 2 . 8 助航設備

助航設備一般用來標示結構物的界限

（如碼頭、裝卸堤、防波堤和船墩）、航

道進口、邊界、彎道及潛在的危險（如淺

灘和礁石），作為船舶的導標，幫助船舶

安全航行。助航設備的種類、尺度、位置、

裝置和附屬設備等，均應符合海事處的要

求。

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Navigation aids covered by this Manual include litand unlit beacons located offshore, on the foreshore orrock outcrops, and on land, and navigation lights onmarine structures. Lights can be mains- or battery-powered as appropriate to the location, and asrequired by the Director of Marine. A beacon locatedoffshore can either be a piled structure, similar to adolphin in design, or a precast reinforced concretegravity structure with enlarged base and rubblefoundation, depending on the sea-bed conditions andwater depth. Generally, single pile dolphins are notrecommended because of their susceptibility toaccidental damage. Beacons located on the foreshoreor rock outcrops can usually be simple precast or castin situ concrete structures doweled to underlying soundrock where possible. The above beacons will all betopped with steel light posts for final light connectionfor lit beacons, or simple steel/concrete marker postsfor unlit beacons. Beacons located on land andnavigation lights on structures will generally only besubjected to dead and wind loads, and simple massconcrete foundations for the light posts or markerposts will usually be adequate.

Ladders, fenders and mooring eyes as appropriateshould be provided for beacons located offshore.Beacons located on the foreshore, rock outcrops andland should be provided with landing facilities, eitherincorporated into the beacon structure or builtseparately. Fittings and fixtures such as ladders,handrails and mooring eyes should be stainless steel.Steel light posts and marker posts should preferably begalvanised after fabrication, and painted with a paintappropriate for the location, taking into account theease of access for future maintenance (see Section14.3.5).

12.9 Outfalls And Intakes

Stormwater outfalls in seawalls and quaywallsshould preferably be located with invert levels nohigher than +0.3 mCD to reduce visual impact,staining, and possible problems with adjacent vessels.In the case of larger sized culverts constructed throughnew reclamations, this requirement may need to be

本手冊涉及的助航設備，包括位於離

岸、近岸、礁石上和陸地上的燈光航標和

不發光航標，以及海事結構上的導航燈。

航燈可用交流電源，也可用電池供電，應

按其位置和海事處的要求而決定。離岸的

航標可按海床的情況和水深，設計成類似

靠船墩的樁基結構，也可採用預製鋼筋混

凝土重力式結構，底部擴大，建於堆石地

基上。一般情況下並不建議使用單樁墩，

因其於意外事故發生時易於毀壞。位於近

岸和礁石上的航標，通常可為預製或現澆

混凝土結構，並盡可能應以榫栓連接到堅

固的基岩上。燈光航標上會裝設鋼製燈

柱，不發光航標可用簡單的鋼或混凝土做

標誌柱。陸上的航標和結構上的導航燈，

一般只承受恒載或風荷載，燈柱或標誌

柱，一般採用無配筋混凝土地基已足夠。

離岸的航標，應按情況備有爬梯、護

舷裝置和繫船環。近岸、礁石上和陸地上

的航標，應備有登岸設施，它可以作為航

標結構的一部分，也可獨立建造。裝置及

輔助裝置，如爬梯、欄桿和繫船環，均應

使用不銹鋼。 鋼製燈柱和標誌柱，應於

裝配後加鍍鋅，並須考慮日後前往該處進

行保養工作的難度後，塗上適當的油漆

（見第 1 4 . 3 . 5節）。

1 2 . 9 排水口和進水口

海堤和裝卸堤的雨水排放口底高程，

不應高於 + 0 . 3 m C D，以減少觀瞻影響、

斑漬污染及干擾附近船舶等問題。但在新

的填海區建造較大暗渠時，為達到水力設

計的標準，可能須要豁免這限制。一些近

期的工程研究，曾將回填高程提高，部分

原因是要容納較高的管道底高程，以減低

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waived in order to produce efficient hydraulic designs.In some recent engineering studies, reclamation levelshave been raised, partly to permit higher invert levels toreduce backwater effects in the drainage systems.Outfalls should be located well clear of pumphouses,intakes and landing steps, and where possible shouldnot be located immediately adjacent to suspended deckstructures, because of possible future dredging accessproblems during desilting.

Outfalls through rubble seawalls usually consist ofprecast concrete units with wing walls on the outerface. Outfalls through concrete blockwork quaywallsare formed in special precast concrete blocks to suit thesize of drainage pipe or culvert. For large box culverts,it is often necessary to form two units with a horizontaljoint at about mid-wall height in order to reduce unitweights to a reasonable level. Wherever possible, liftinghooks for precast concrete outfall units should beformed in recesses which can be filled with suitablegrout or concrete after unit setting; in this way, liftinghooks need not be removed and are available forfuture use during demolition or future modification.Seals between outfall units are not usually necessary butshear keys are often provided. Where outfalls areconstructed in advance of drainage pipes or boxculverts, the outfalls should be temporarily sealed bytimber boards, brickwork, concrete or steel plates asappropriate for the opening size; the loads on thetemporary seals from waves, water pressure and soilpressure should be assessed.

Intakes are usually formed in concrete blockworkquaywalls to provide seawater for pumping stations,and are usually constructed concurrently with thequaywall. Size and location of the intake will bedetermined by the client. The invert level should bedesigned to ensure a continuous supply of water,unaffected by waves, tides, currents and watertemperature variations. The usual method ofconstruction is to use precast concrete units for the baseslab and lower walls, and cast in situ concrete for theupper walls and roof slab. Joints between precastconcrete units are usually required by the client to besealed.

排水管系統的回水作用。排水口的位置，

應遠離泵房，進水口和登岸台階，亦盡量

不要設在承台式結構附近，因為疏浚排水

口附近的淤積時，可能會在安排通道上出

現問題。

堆石海堤的排水口，一般由外部帶翼

牆的混凝土預製件構成，混凝土方塊裝卸

堤的排水口，則利用混凝土預製塊體，特

別設計以適應排水管或暗渠的尺度。對於

大型箱形暗渠，通常要分為上下兩個單元

構件，在牆的中央連接，以減少構件重

量。吊 應盡可能在混凝土排水口預製件

上形成的凹槽裏安裝，於構件固定後，可

用水泥漿或混凝土將凹槽填補。採用此種

方法，吊 可以不用除掉，以備將來拆卸

或改建時使用。出水口構件之間一般不用

密封，但常帶有抗剪鍵。若排水口工程在

排水管或暗渠完成前進行，須用木板、磚

砌體、混凝土或鋼板將排水口臨時封上；

該封口的設計，應考慮到波浪、水壓力和

土壓力的荷載。

為方便泵站抽取海水的進水口，通常

會建於混凝土方塊裝卸堤上，一般進水口

及堤墻會同時建造。進水口的大小和位置

會由委托人決定。管道內底高程的設定，

應確保供水能連續不斷，不受波浪、潮

汐、水流和水溫變化影響。常用的施工方

法，是用混凝土預製底板和牆體下截；牆

體上部和頂板則用現澆混凝土。通常委托

人會要求預製件和現澆件之間的接縫要

封好。

建議進水口和排水口的鋼筋混凝土，

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It is recommended that reinforced concrete foroutfalls and intakes should have a characteristic strengthof 45 MPa, and should be in accordance with Section11.4.

12.10 Miscellaneous

Measured mile markers or transit markers aremarker posts erected in conspicuous locations on land,and used by the Marine Department for carrying outvessel speed trials. Two pairs of marker posts are used,each pair separated by a known fixed distance, and thelines joining the marker posts in each pair perpendicularto the known fixed distance. It is recommended thatthe ratio between the distance between each markerpost in each pair, and the distance between the vesseltrial line and the nearest marker post, should be not lessthan one third. Details of the size, height, and locationsof marker posts are usually determined by the Directorof Marine. Steel tubular marker posts are usually usedwith steel guy ropes as necessary, and mass concretefoundations.

Concrete mooring blocks are normally precast insizes of ½, 1, 2, 3, 5, 10, 15, 25, 50 and 90 t. Combinedlifting and anchor hooks are provided for the fivesmallest sizes, and separate lifting and anchor hooks forthe larger sizes. The 90 t mooring block consists of a50 t main block and a separate 40 t saddle block whichcan be placed on top. Concrete for mooring blocks isusually unreinforced for the smaller sizes, andnominally reinforced for the larger sizes, excludinglifting and anchor hooks; concrete with a characteristicstrength of 30 MPa is considered appropriate, as theblocks are fully immersed during use.

特性強度應為 4 5 M P a，並應按第 1 1 . 4節

所述的要求澆注。

1 2 . 1 0 其他

經實測確定的里程標或稱航行標，是

海事處用來測量船速而豎立在顯著陸上

位置的標誌桿。里程標由兩對標誌桿組

成，每對均按固定的距離分隔，每對之間

的連線都垂直於已確定的距離。每對標誌

桿的間距，和船速測定路線，與最近的標

誌桿的距離的比率，不應小於三分之一。

標誌桿的大小、高度及位置等細節，通常

由海事處決定。其結構一般採用鋼管桿，

按需要裝上鋼絲繩，並用無配筋混凝土式

地基。

混凝土繫船塊，一般按1 / 2、1、2、3、

5、1 0、1 5、2 5、5 0和 9 0公噸的規格預製。

規格最小的五種，備有起吊和錨定兩用

，其餘體積較大的則分別備有吊 和錨

定 。 9 0公噸繫船塊，由一個重 5 0公噸

的主塊體，和一個可置放其上，重 4 0公噸

的鞍形塊體構成。通常較小混凝土繫船塊

均無配筋，而較大繫船塊則會加上額定鋼

筋，但不應將吊 和錨定 計算在內。由

於繫船塊使用時全部浸沒於水裏，所以可

用特性強度為 3 0 M P a的混凝土。

124

125

13. CONSTRUCTION

13.1 GENERAL

This Chapter covers current practice in thesupervision and the keeping of site records fordifferent types of work and construction, includingdredging, breakwaters and seawall foundations,concrete blockwork walls, piers and dolphins,reclamations and underwater blasting. Comments aregiven on aspects which require particular attention.

13.2 DREDGING

13.2.1 General

For capital works dredging, it is important todistinguish between foundation dredging which isrequired for breakwaters, seawall foundations andsubmarine pipelines, and navigation dredging which isrequired for new fairways and approaches to piers andferry terminals. Maintenance dredging is coveredseparately in Chapter 14, although many aspectscovered in this Chapter related to navigation dredgingalso apply to maintenance dredging.

For foundation dredging, which is usually carriedout in trenches, the quality of the remaining material atfoundation level is of primary importance; fornavigation dredging, the finished dredging level is themost important consideration. For foundationdredging, the stability of trench side slopes is of onlysecondary importance as these are required to be stableonly temporarily until the trench has been filled withfoundation material. For navigation dredging, thestability of any side slopes is of major importance asthese are required to be stable under long termconditions covering current and wave extremes.

13.2.2 Preparation and Execution of Works

Before any dredging works commence on site, it is

1 3 . 建造

1 3 . 1 概述

本章論述現行監督工程和保存工地記

錄的方法，涉及的工程包括挖泥、防波堤

及海堤地基、混凝土方塊體牆、碼頭及船

墩、填海和水底爆破。本章提及施工時各

樣須特別注意的地方。

1 3 . 2 挖泥

1 3 . 2 . 1 概述

進行基建挖泥時，須區別是地基開

挖，還是航道開挖。地基開挖是指防波

堤、海堤及水底管道所需的挖泥，而航道

開挖是指新建碼頭和渡輪碼頭的主航道

和引航道所需的挖泥。第 1 4章將獨立論述

維護性疏浚，但本章提及許多關於航道開

挖的要點，也適用於該類工程。

地基開挖通常會形成基坑，地基底部

的土質非常重要；基坑邊坡的穩定性，相

對地屬次要，因為只要求它在回填前，能

保持暫時的穩定。至於航道開挖，完成挖

泥後的深度，固然是首要考慮，邊坡的穩

定性也相當重要，因為航道的邊坡，須要

長期經受水流和波浪作用，期間可能出現

極端條件，但仍須保持穩定。

1 3 . 2 . 2 施工準備和執行

在現場開展挖泥工程之前，要確保承

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important to ensure that the contractor has erectedsufficient land marks, and for the location of all landmarks and the levels of all temporary tide gauges to bechecked by land surveyor. The use of land marks andtide gauges will not be possible for some types ofnavigation dredging remote from the shore; in thesecases, position checking will usually be by electronicdistance measurement from shore stations, with thepossible assistance of buoys for on-site cross checking,and level checking will be by interpolation from thenearest standard tide gauge stations.

Before dredging commences, a detailed initialsounding survey of the seabed should be undertakenjointly with the contractor and agreed for record andmeasurement purposes. Throughout the dredgingworks, a daily record of dredging should bemaintained. Dredged quantities for interim paymentpurposes are usually estimated by assessing the quantityin each barge and applying a reduction factor, whichshould be agreed with the contractor, to take accountof bulking and possible overdredging. An initialreduction factor for marine deposits of 0.6 issuggested. Reduction factors should be regularlychecked and adjusted as necessary using interimsurveys, or final surveys, as sections of the works arecompleted.

Upon completion of dredging, a detailed finalsounding survey of the dredged area should beundertaken jointly with the contractor and agreed.Calculation of final quantities for payment purposes isusually based on the initial and final sounding surveys,as proposed by the Standard Method of Measurementfor Civil Engineering Works (Hong KongGovernment, 1992b).

13.2.3 Sampling of Dredged Materials

Samples of dredged materials should be taken atregular intervals, and at any change in stratum ormaterial quality in general. As a guide, for foundationdredging in a trench, with uniform material, samplesshould be taken at about 15 m centres along the line ofthe trench and 2 m centres vertically. Each sampleshould have a mass of about 1 kg and should

建商豎立足夠的界標。所有界標的位置和

臨時潮位計的標高，均須經土地測量師檢

核。若航道開挖遠離岸邊，不宜使用界標

和潮位計，則一般會在岸邊測站用電子測

距法檢測位置，可借助現場浮標校核，至

於標高，則用鄰近的驗潮站資料，使用內

插法檢核。

挖泥開始前，須和承建商共同進行詳

細的首次海底測深，數據須和承建商共同

確定，留作記錄並用來計算工量。挖泥工

程進行期間，每天須記錄挖泥資料。計算

階段性付款時，須估算挖泥量，通常會先

估計每條運泥船的泥量，再乘以一個與承

建商協議的折減系數，以顧及濕脹及可能

的超挖量。海相沉積土的折減系數，最初

可定為 0 . 6，待進行了中期測量及竣工部

分的最後測量後，便可定期用這些結果，

校核和調整該折減系數。

挖泥完成後，須和承建商共同在挖泥

區進行詳細的最後海底測深，該測深結果

須與承建商共同確定。按照《 S t a n d a r d

M e t h o d o f M e a s u r e m e n t f o r C i v i l

E n g i n e e r i n g W o r k s 》 ( H o n g K o n g

G o v e r n m e n t , 1 9 9 2 b ) 的建議，計算最後

應付款的挖泥量時，一般以首次和最後海

底測深的結果為依據。

1 3 . 2 . 3 挖出物取樣

每隔一定距離，或在地層和泥沙性質

有變化的地方，應從挖出的泥沙中取樣。

在土質一致的基坑進行地基開挖時，須沿

基坑中心線每隔1 5米和中心線垂直方向

每隔 2米處取樣。每次取樣量約一公斤，

及盡量取自抓斗或鏈斗的中央部分，若是

採用耙吸式挖泥船，則應從在把挖得物料

127

preferably be taken from the centre of a grab or bucketload; for a trailer suction dredger, the sample should betaken from the pipe discharging into the hopper.Samples should initially be placed in clear plastic bags,all air expelled and the bags sealed with plastic tape.Labels should be attached with the followinginformation included :

(a) contract no.,

(b) location,

(c) depth and level,

(d) time and date,

(e) dredging method,

(f) material description, and

(g) sand percentage (if available).

Samples need normally only be kept until thecompletion of all dredging work and finalisation ofdredging quantities. Where it is necessary to keepsamples for more than a few months, for examplewhere there may be contractual claims, the samplesshould be transferred to air-tight clear glass jars forstorage. All samples should be kept in the site office,together with a summary in table form of theinformation included on the labels attached to thesamples.

When carrying out foundation dredging, forsamples taken from depths close to the proposeddredge profile, the sand content should be determinedon site. As a guide for checking the suitability ofmaterial at the bottom of a dredged trench for aseawall or quaywall foundation, common practice is toaccept material with a sand content not less than 70%by weight, subject to checking with the designcalculations in each case. The basis for this rule ofthumb is that normal specifications for sand filling andunderwater filling material in general allow the use ofmaterial with up to 30% by weight passing aBS No. 200 (63 micron) sieve. In general, it is notconsidered necessary to remove material from the

排放進泥艙的管道中取樣。樣本應放入透

明的塑膠袋內，然後排出袋內的空氣，用

膠貼封口，貼上填有下列資料的標簽﹕

( a ) 合約編號，

( b ) 位置，

(c) 深度和高程，

( d ) 時間和日期，

( e ) 挖泥方法，

( f ) 挖出物料說明，及

( g ) 含沙率 (如有 )。

通常，泥土樣本會保留下來，直到完

成挖泥工程，及確定挖泥量後為止。若因

有合約索償等原因而須保留樣本數月以

上，應將它們轉存到密封的透明玻璃瓶

裏。所有樣本，連同記有標簽上資料的一

覽表，均應存放在工地辦公室內。

進行地基開挖時，取自原定挖泥深度

附近的泥土樣本，應在現場確定含沙率。

在海堤或裝卸堤的基坑，常用的標準是其

底部的泥土含沙率不少於總重量的 7 0

﹪，當然，這須按個別情況，先核對設計

計算書後才確定。一般的砂和水下填料規

格，容許通過 B S 2 0 0號篩（ 6 3微米）的

泥粒重量可達總重量的 3 0﹪，這便是以上

簡單方法的依據。基坑底部的泥土，如其

含沙率與填料相若，通常便不用挖去。當

然，如果基坑的底質是硬黏土，上述方法

便不適用。若在設計階段發現這種情況，

地基底部土質的取捨準則，便應在合約內

訂明。

128

bottom of a dredged trench if this material is to bereplaced by filling material with a similar sand content.Of course, the above guide should not be used whenthe foundation material at the bottom of a dredgedtrench is a stiff clay. Such conditions should normallybe identified at the design stage and alternativemeasures to determine the suitability of the foundingmaterial should be specified in the contract.

Reference should be made to the design calculationsto ensure that the material properties at the bottom of adredged foundation trench assumed in the design are infact attained. When the clay content is low, it may bepossible to reduce the depth of dredging if materialwith a sand content exceeding 70% is reached beforethe required depth shown on the original profile. If therequired depth is reached and the material has a sandcontent of less than 70%, it may be necessary for thetrench to be deepened or widened, or both. A designcheck should be carried out before such variations areimplemented. It is recommended that importantdesign assumptions are indicated on the drawings toassist in such checks.

13.2.4 Surveys for Dredging

Section 21 of the General Specification for CivilEngineering Works (GS) (Hong Kong Government,1992a) requires the final survey for dredging to becarried out within 30 days after completion ofdredging, and states that dredging should be carriedout in such a manner and sequence that semi-fluid ordisturbed seabed and foundation material will notaccumulate in the dredged areas. For foundationdredging in a trench, it is important to check that therehas been no significant deposition or accumulation ofsoft deposits in the bottom of the trench betweencompletion of dredging and the start of filling withfoundation material. This is particularly importantwhen there has been a period of high waves during astorm. Such checking can be carried out by diver, grabsampling or repeat survey, or preferably a combinationof these.

施工時須參考設計計算書，以確保基

坑底部的土質特性，已達到設計的標準。

如果基坑的黏土含量低，開挖尚未達到原

本要求的剖面深度前，底部土質含沙率已

超過 7 0﹪，可減低挖泥深度。如果開挖已

經達到所要求的深度，但底部土質含沙率

仍低於 7 0﹪，便可能要加深或拓寬基坑，

或兩者兼用。在改動之前，須先驗算設

計，因此，為便利驗算，建議在圖則中註

明重要的設計假定。

1 3 . 2 . 4 挖泥測量

《 G e n e r a l S p e c i f i c a t i o n f o r C i v i l

E n g i n e e r i n g W o r k s》（下稱《G S》） (HongKong Government, 1992a) 第 2 1節規定，須

在挖泥結束後 3 0天內進行最後測量，該節

亦指出挖泥工序須避免半流質或受擾動

的海床及地基底部物質沉積在已挖區域

內。若屬基坑開挖工程，在開始回填地基

物料之前，須特別查驗在完成挖泥後，坑

底並無大量的沉積或淤積。若期間曾經歷

風暴所引起的大浪，這點尤為重要。檢查

可由潛水員進行，也可用抓斗取樣，或重

新測量，更好的是綜合使用這幾種方法。

129

Section 21 of the GS states that surveys fordredging should be carried out by echo sounders of200 to 220 kHz frequency or other methodsspecified by the Engineer. It is important to arrangefor echo sounding results to be checked using chainsounding, particularly for foundation dredging intrenches and where the presence of mud in suspensionis suspected. Mud in suspension can be a majorproblem in deep trenches where soft marine depositshave been recently dredged; in some cases, the rate ofsettlement of the mud is extremely slow, possibly dueto continuous disturbance due to the passage of vessels,wave effects and currents. Differences of severalmetres between echo sounder and chain soundingresults in deep trenches have been experienced, evenafter several days following the completion ofdredging. For such cases it has been necessary toignore the echo sounder results and to use chainsounding for the final trench survey.

Problems with echo soundings being reflectedfrom mud suspensions can be investigated by takingsamples by diver at different depths and by using agravity corer. For navigation dredging, information onthe density of bottom sediments in relation to 'nauticaldepth' is given in Section 2.4.

Even where there are no apparent problems withecho soundings being reflected from mud suspensions,there will often be difficulties in interpreting echosounding traces, due to aspects such as wavemovements and beam widths. Each trace should bediscussed with the surveyor, and contractor ifappropriate, for each case, before determining themost appropriate interpretation under thecircumstances. For different situations, it may beappropriate to use the high, mean or low reading fromthe trace at a particular point to represent the bed levelat that point, or to use the mean of all the high and lowreadings from the trace between two points torepresent the bed level midway between the twopoints. For payment purposes, the use of meanreadings is considered generally to be the mostreasonable and appropriate interpretation. Foracceptance purposes, particularly for navigation

《G S》第 2 1節指出，挖泥測深時，須

用頻率 2 0 0至 2 2 0 k H z的聲納測深儀或工

程師指定的其他方法。要注意聲納測深的

結果應用鏈測深檢核，特別是開挖基坑

時，因可能受懸浮泥漿影響，更應留意。

對剛完成軟土挖掘的深基坑來說，懸浮泥

漿可能是個大問題。在某些情況下，由往

來船隻、波浪、水流作用而引起的連續擾

動，會使懸浮泥漿沉降變得極其緩慢。因

此，即使挖泥數日後，用聲納與用鏈測深

在深基坑中錄得的結果，也可能相差數

米。在這情況下，可放棄聲納測深，而以

鏈測深結果為基坑深度的依據。

懸浮泥漿對聲納測深的影響，可用重

力式取樣管，或藉潛水員在不同深度取樣

研究。有關航道開挖工程，「通航深度」

與海底沉積物密度的關係資料載於第 2 . 4

節。

即使懸浮泥漿對聲納測深影響不大，

但由於波浪運動和聲束寬度的影響，聲納

測深得到的掃描往往不易分析。這時應先

與測量師商討，必要時還要與承建商研

究，才能作出最合理的判斷。掃描須按個

別情況分析，在一個定點，可能會用掃描

的高、中或低讀數來代表該點的海底高

程，又或者用在兩點之間掃描的所有高、

低讀數的平均值，來代表該兩點的中間位

置的海底高程。計算工程付款時，一般認

為取中間讀數最為合理。驗收時，通常採

用掃描的高讀數較為恰當，特別是在開挖

航道時，由於個別的高點可能會引致嚴重

後果，這點便更為重要。

130

dredging where isolated high spots may be critical, theuse of the high readings from the trace will generally bemore appropriate.

For foundation dredging, when a section of trenchhas been completed and the profile checked bysounding survey and sampling, approval of the profileshould be recorded and agreed with the contractor.No filling material should be placed in the section oftrench under consideration until the relevant approvalhas been recorded.

13.2.5 Dumping of Dredged Material

It is not usually necessary to physically ensure thatdredged materials are dumped at gazetted marinedumping grounds, as this is a legal requirement of thedumping licence issued by and policed by theEnvironmental Protection Department. However,periodic checks should be made that the contractor'sbarges are properly licensed and have appropriatedumping licences. The periods between the bargesleaving full from the site and returning empty to the siteshould also be checked to ensure they are compatiblewith the time the trip to the appropriate dumpingground should take.

13.3 BREAKWATERS AND SEAWALL FOUNDATIONS

13.3.1 General

This Section covers sand and rock filling and theplacing of rock armour for breakwaters and seawallfoundations, although many aspects covered also applyto foundations for other marine structures and rubblemound construction in general.

13.3.2 Preparation and Execution of Filling

Prior to any filling or placing work, as for dredging,it is important to ensure that sufficient land marks andstagings have been erected and that the location ofthese and the levels of all temporary tide gauges have

在完成了地基開挖的一段基坑，而其

剖面又已經測深和取樣檢核後，便須與承

建商確定，將這一段認可的剖面記錄下

來。任何一段基坑，在未有認可記錄之

前，不應拋放回填料入內。

1 3 . 2 . 5 傾卸挖出物

挖泥物料須於憲報刊登的海上卸泥區

傾卸，這是環境保護署發出的卸泥許可證

的規定，由該署執行，因此，通常不用監

督每艘運泥船卸泥。但是，仍須定期檢查

承建商的運泥船有無適當的牌照及卸泥

許可證，也要查核運泥船滿載離開工地與

空載返回之間的周期，以確保與其來往卸

泥區所需的時間相符。

1 3 . 3 防波堤及海堤地基

1 3 . 3 . 1 概述

本節論述防波堤及海堤地基的砂、石

回填，以及護面塊石的堆放，所提及的許

多要點，也基本上適用於其他海事結構的

地基，和一般的堆石結構施工程序。

1 3 . 3 . 2 回填的準備與實施

與挖泥一樣，在進行任何回填和堆放

作業之前，首先要豎立足夠的界標和標

架，並檢驗其位置和所有潮位計的標高。

131

been checked, if this has not already been done forprior dredging work.

A daily record of filling and placing should beprepared. As for dredging, quantities for interimpayment purposes can be estimated by assessing thequantity in each barge and applying a reduction factor,in this case to take account of waste, loss, consolidationand possible dumping outside the required profile.Initial reduction factors for sand filling and rock fillingof 0.7 and 0.65 respectively are suggested and shouldbe agreed with the contractor. Reduction factorsshould be checked regularly and adjusted as necessaryusing interim surveys, or final surveys as sections of theworks are completed. Upon completion of filling orplacing each material, final detailed surveys should betaken jointly with the contractor and agreed. Thesesurveys form the basis for measurement and payment,in accordance with the Standard Method ofMeasurement for Civil Engineering Works (HongKong Government, 1992b).

Section 21 of the GS requires rock in armour layersand underlayers in rubble mound construction to beplaced working from the bottom to the top of asection, in such a manner and sequence that theindividual rock pieces interlock and do not segregateand the interstices are kept free of small rockfragments. These requirements are particularlyimportant as they relate directly to design assumptionscovering stability against wave attack and wave run-up.There should be no free pieces on the surface of acompleted layer, and all pieces should be wedged andlocked together so that they are not free to movewithout disturbing adjacent pieces in the same layer.For rock armour layers and underlayers above waterlevel, final visual inspections from the top of the slopeand by boat from the bottom of the slope should becarried out in addition to the normal profile check bysurvey. Below water level, a final visual inspection bydiver is recommended where possible, depending onvisibility, particularly for rock armour layers. If anysignificant holes or areas with infilled interstices aredetected, whether above or below water level, it will bedifficult for these to be satisfactorily rectified withoutalmost complete reconstruction of the adjacent areas.

回填和鋪放的資料，必須每日記錄下

來。與挖泥一樣，當要估算工量以計算階

段性付款時，可先估計每條躉船的容量，

再乘以折減系數，以顧及物料損耗、流

失、固結及被拋到指定剖面以外的可能

性。砂和石填料的折減系數，應與承建商

協定，初時可定為 0 . 7和 0 . 6 5，以後可利

用階段性測量和分段工程竣工時的最後

測量結果，作定期的檢核和調整。各種材

料回填和鋪放完成後，應與承建商共同進

行詳細的最後測量，測量結果須與承建商

共同確定。按照《 S t a n d a r d M e t h o d o f

M e a s u r e m e n t f o r C i v i l E n g i n e e r i n g

W o r k s 》 ( H o n g K o n g G o v e r n m e n t ,

1 9 9 2 b ) 的規定，計算工量與付款，都是

以這些測量結果為依據。

《G S》第 2 1節規定，舖放堆石基床時，

護面層和墊層的塊石，應從剖面底部依次

鋪放到頂部，施工的方法要保證塊石相互

聯結，不致分離，而且無零碎石塊留在空

隙內。這些規定直接來自計算抗波浪 擊

和波浪上衝穩定性時的設計假定，因此十

分重要。在已完成的回填層表面，不應有

鬆脫的塊石，而所有塊石均應楔緊並固鎖

在一起，使每塊塊石都不會單獨移動。水

位以上的塊石護面和墊層，除了通過測量

對剖面進行常規檢測外，還應從斜坡頂部

及乘船在斜坡底部進行目測檢驗。建議在

可能情況下，應視乎能見度由潛水員目測

檢驗基床在水位以下的部分，特別是護面

層，更應注意。不論在水位以上還是以

下，如發現有明顯的孔洞或有空隙遭填

塞，均須和相鄰的護面層一起全部重鋪，

才能達致滿意的效果。

132

Where filling or placing for a section of the workhas been completed, and the profile checked by surveyand inspection, approval of the profile should berecorded in the Site Instruction Book andcountersigned by the contractor. No overlying workshould be started for the section under considerationuntil the relevant approval has been recorded.

13.3.3 Surveys for Fill Materials

Section 21 of the GS states that surveys for thedeposition of fill material should be carried out byecho sounders of 200 to 220 kHz frequency or othermethods specified by the engineer. As for dredging,echo sounding results should be checked using chainsounding, although mud in suspension is less likely tobe a problem in this case. Difficulties in interpretingecho sounder traces are covered in Section 13.2. Forfill material, the use of mean readings for paymentpurposes and low readings for acceptance purposes issuggested, but this should be discussed with thesurveyor, and contractor if appropriate, for eachparticular case.

Rock filling and rock armour above water level willneed to be surveyed using a levelling staff. The methodof survey should be agreed with the surveyor beforework starts, to ensure that readings are taken at trulyrepresentative points but that any high and low spotsare also identified.

13.3.4 Tolerances for Fill Materials

Tolerances for the deposition of sand fill, rock filland rock armour are covered in Section 21 of the GS.It is usual practice, particularly for concrete blockworkwalls, for the level of the top of the rock fill infoundation construction to be raised above therequired design level to allow for subsequent settlementduring the construction period. The amount of set-upshould be proposed by the contractor, and checkedand agreed by the engineer. The amount depends on

當一段堤身回填或堆放完成，且已對

該剖面進行了測量和目測檢驗後，應在工

地指令冊記錄下該段已認可驗收，並經承

建商確認。在未有認可驗收記錄的堤身

上，不應覆蓋其他填料。

1 3 . 3 . 3 回填測量

《G S》第 2 1節指出，檢核填料的回填，

應使用頻率 2 0 0至 2 2 0 k H z的聲納測深儀

或由工程師指定的其他方法。儘管在回填

時，懸浮泥漿可能不是主要問題，但仍應

與挖泥一樣，用測深鏈檢核聲納測深的結

果。第 1 3 . 2節論述了分析聲納測深掃描所

遇到的困難。計算工程費用時，建議採用

掃描的中間讀數，而驗收時則採用低讀

數。遇上特殊情況，應與測量師研究，必

要時還應與承建商商討。

水位以上的石填料和塊石護面，須用

測量尺量度。測量方法在施工前，便須與

測量師商定，以確保讀數既具有代表性，

也可以顯示可能出現的高點和低點。

1 3 . 3 . 4 回填容許誤差

《G S》第 2 1節論述了砂、石填料和護

面塊石的施工容許誤差。在建造地基時，

特別是對於混凝土方塊體牆，通常會將填

石的頂部高程提高，超過設計規定的高

程，以彌補施工期間的沉降。調整量應由

承建商提出，並經工程師檢核和同意，其

大小取決於許多因素，包括地基下土質的

特性，填砂和填石的厚度、地基上結構的

重量以及預計的施工期等。對於一般的混

凝土方塊體牆工程，預計調整值會在 1 0 0

133

many variables, including the characteristics of theunderlying foundation material, the thickness of thesand and rock filling, the mass of the works to beconstructed on the foundation, and the expectedconstruction period. As a guide, for normal concreteblockwork wall construction, a set-up of betweenabout 100 and 300 mm would be expected.

13.4 CONCRETE BLOCKWORK WALLS

13.4.1 Levelling Stones and Blocks

Normally, no packing pieces are allowed at verticalor horizontal joints between precast concrete blocks;therefore the ease and accuracy with which a concreteblockwork wall can be constructed is greatlydependent on the accuracy in shape and size of theblocks being used, and the accuracy and consistency ofthe levelling stones on top of the rubble moundfoundation. It is important for the levels of the rails orother profile marks to be checked by surveyor beforethe laying of the levelling stones starts, and for thelevelling stones to be inspected by diver before anyblock setting.

Daily records for the casting and setting of blocksshould be kept. In addition, record drawings givingthe date of setting of each block should be kept in thesite office. After the setting of each layer of blocks hasbeen completed, a diving inspection should be carriedout to check such matters as the accuracy of setting,joint widths, infilling of channels between adjacentblocks and cleanliness of the top surface for receivingthe next layer of blocks.

13.4.2 Bermstones

Section 21 of the GS requires bermstones to beplaced as soon as practicable after the setting of toeblocks. Bermstones are required to prevent scour offoundation material from immediately in front of thetoe blocks due to waves and currents, and earlyplacement is particularly important when one or moreof the following conditions apply :

到 3 0 0毫米之間。

1 3 . 4 混凝土方塊體牆

1 3 . 4 . 1 整平石與方塊

混凝土預製塊的垂直和水平接縫間，

通常不可以用墊塞物。因此，預製塊形狀

和大小的準確性，以及堆石基床頂部的整

平碎石的精確和均勻程度，均十分重要，

以確保方塊體牆的施工過程順利和免於

誤差。鋪放整平石之前，首先要由測量師

檢驗整平線和其他剖面標誌的高程，再在

安放混凝土預製塊之前，由潛水員檢查碎

石的整平情況。

日常記錄應包括混凝土方塊的澆注和

安放資料。工地辦公室應存有記錄圖，記

下混凝土塊的安放日期。每層方塊安放完

成之後，須進行水下檢測，確定安放的準

確度、接縫寬度、相鄰混凝土方塊間半圓

槽的充填情況，以及方塊頂的清潔程度，

以便鋪放下一層預製塊。

1 3 . 4 . 2 護腳石

《G S》第 2 1節規定堤腳塊體鋪放好後，

應盡快鋪放護腳石。護腳石的作用，是防

止波浪及水流將堤腳前端的地基材料

走，因此，遇到下列的情況時，應及早鋪

放護腳石﹕

134

(a) the location is subject to strong currents,

(b) the location is exposed to wave attack,

(c) block setting is to be carried out in the seasonwhen tropical storms may be frequent, or

(d) the toe level of the wall is higher than -3 mCD.

The placing of bermstones should be checked bydiver. It is important that the bermstones shouldextend over the foundation width required, that thegaps between bermstones are kept to the minimum,and that no part of any bermstone extends above thelevel of the top of the adjacent toe block.

13.4.3 Facing Stones and Copings

The construction of in situ concrete copings and thepointing of facing stones should preferably be carriedout as late as possible in the construction programmefor each section of wall in order to minimise the effectsof wall settlement. Subject to user requirements, it iscommon to allow the contractor to delay these twoitems of work until towards the end of themaintenance period. If it is necessary for any bollardsto be used during the maintenance period, at least thesections of coping adjacent to each bollard foundationshould be constructed together with the bollard beforea certificate of completion for that section of the worksis issued.

13.5 PIERS AND DOLPHINS

13.5.1 Preparation of Works

The location of all temporary setting-out marks andthe levels of all temporary tide gauges should bechecked by surveyor before any piling or otherconstruction work starts on site. For a driven pile, thelocation and rake of the pile should be checked afterpitching before driving starts, and for a bored pile, thelocation of the casing should be checked before anyexcavation is carried out.

( a ) 位於水流急速的地方，

( b ) 位於受波浪 擊的地方，

(c) 在熱帶風暴頻密的季節安放塊體，

或

( d ) 堤腳高程高於 - 3 m C D。

護腳石的鋪放情況應由潛水員檢驗。

注意護腳石應伸延至地基所需寬度以

外，塊石之間的空隙要盡量縮窄，其頂部

更不可以超越堤腳塊體頂部的高程。

1 3 . 4 . 3 護面石和牆帽

計劃牆體的施工程序時，應盡量推遲

現澆混凝土牆帽和面層石勾縫的建造，以

減低牆體沉降的影響。一般情況下，若與

土地使用者要求無砥觸，可以允許承建商

將這兩項工序延至接近保養期結束的時

候。但如在保養期中須使用繫船柱，則應

在發出該段工程竣工證書之前，完成繫船

柱及與其基礎相鄰的牆帽。

1 3 . 5 碼頭和船墩

1 3 . 5 . 1 施工準備

在打樁和其他現場工序開始之前，測

量師應檢驗所有臨時施工標誌的位置和

臨時潮位計的標高。在完成定位後的打入

樁，應在打樁工序開始前檢驗樁的位置和

傾斜度。鑽孔灌注樁，則應在開挖之前檢

驗鋼管的位置。

135

Tidal work requires careful planning to ensure thatall available working time at low tide is efficiently used.Charts should be drawn up from the tide tables, takinginto account past records, to assist with planning work.The contractor should be reminded to apply for aConstruction Noise Permit, if required, well in advanceof the planned date of the work, if tidal work isrequired to be carried out outside normal workinghours.

When checking any contractor's temporary stagingsand temporary works designs, care should be taken totake into account the effects of the following :

(a) wind pressure,

(b) wave loads including possible uplift,

(c) construction materials,

(d) formwork and falsework,

(e) plant, equipment and workmen, and

(f) dynamic (impact) loads.

13.5.2 Piling

Temporary stagings for pile driving plant andequipment should take particular account of pileweights during pitching and during the driving ofraking piles.

Section 8 of the GS requires all marine piles to bedriven from fixed stagings unless approved otherwiseby the engineer. There is the likelihood of damage toprecast concrete piles driven from a barge, especially atexposed sites. Under certain circumstances, piledriving from a barge may be acceptable for relativelyprotected sites, particularly where steel piles are to beused. Large piling barges should be used, and thecontractor should demonstrate that pile damage duringdriving due to barge movements is very unlikely.

為確保能有效地利用低潮期間施工，

各項工序須作周詳安排。應根據潮汐表，

及以往的記錄來繪製圖表，以協助制定施

工計劃。應提醒承建商，如有需要在正常

工作時間以外，利用低潮施工，須在事前

申請建築噪音許可證。

查驗承建商的臨時打樁架和臨時工程

設計時，須考慮到下列因素的影響﹕

( a ) 風壓力，

( b ) 波浪荷載，包括可能產生的浮托

力，

(c) 施工材料，

( d ) 模板和臨時支撐，

( e ) 設備、裝置和工人，及

( f ) 動力（撞擊）荷載。

1 3 . 5 . 2 打樁

在斜樁的定位和打入過程中，須特別

注意樁重對承載打樁機及設備的打樁架

的影響。

《G S》第 8節規定，除非工程師另行

批准，所有海事工程的樁均應從固定樁架

施打。從躉船上打的混凝土預製樁容易損

壞。如果是在開敞的水域進行，情況會更

嚴重。在特定情形下，特別是在使用鋼樁

時，才可容許在掩蔽的地方利用躉船打

樁。但應使用大型的打樁船，而且承建商

要通過實地試驗，證明不會因躉船在打樁

過程中移動而損壞樁柱。

136

The provision of temporary supports for drivenpiles during driving, and until incorporation into thesuperstructure, is covered in Section 8 of the GS. Formarine piles it is important to ensure that bracing to pileheads, in two directions at right angles, is providedimmediately after driving, to prevent the possibility ofoscillation in the cantilever mode due to current andwave forces.

In addition to ensuring that the pile driving orinstallation records are kept in accordance with Section8 of the GS, a drawing showing the location andreference mark of each pile, the date of driving orinstallation, sea bed and pile toe levels, and final set foreach pile if applicable, should be prepared and kept upto date on site.

For precast concrete piles, a record giving the pilereference mark, size, length and date of casting shouldbe kept on site, together with the dates of tensioningand strand cutting if applicable. It is normal practicefor the contractor and engineer jointly to keep a recordof all relevant data relating to piling in the contract. It isimportant to check that precast concrete piles are liftedand supported at the specified points and generallyhandled with care.

13.5.3 Fendering

It is normal to delay final fender fixing until as late aspossible in the construction period, to reduce thepossibility of damage by construction plant to theminimum. It is important that any cast-in fixing boltsare adequately protected against corrosion anddamage, prior to the fenders being fixed.

13.5.4 Works by Others

When facilities such as lights, cables, pipes, lifts andramps are to be installed by other agencies during theworks, particular attention should be paid to co-ordinating the different parties. The overallconstruction programme should take into account

《G S》第 8節列明打入樁在打樁過程

中，和完成後但未與上蓋結構連接時的臨

時支撐要求。打樁後，為防止可能由水流

力和波浪力引起的懸臂式搖擺，應即時將

樁頭在兩個垂直的方向加上支撐而連接

起來。

在施工時，除了要按照《G S》第 8節

的規定，記錄樁柱的打入或安裝資料外，

還須用圖樣按情況標明每根樁的位置、參

考標誌、打樁或安裝日期、海底和樁底高

程，以及每根樁的最終貫入度。在施工期

間，這份記錄圖應保存在工地內，並經常

加上最新的資料。

若採用的是混凝土預製樁，工地應保

存有關樁的參考標誌、規格、長度和澆注

日期等記錄，還應記下施加拉力和切割預

應力鋼纜的日期。通常，承建商和工程師

會共同記錄有關打樁工程的全部資料。若

採用的是混凝土預製樁，便應檢查起吊和

支撐點是否符合原來的規定，及注意操作

時要小心謹慎。

1 3 . 5 . 3 護舷設備

一般做法是盡量在施工期最後階段才

安裝護舷設備，以減低施工時其他機械對

護舷設備所造成的破壞。在安裝護舷設備

之前，應注意妥善保護預埋的螺栓，以防

銹蝕及損壞。

1 3 . 5 . 4 協調工作

施工期間，燈、電纜、管線、起重機

和滑道等裝置通常由其他部門或機構安

裝，故應特別注意與它們的協調問題。全

面的施工計劃，要顧及須預先通知各部門

及機構，和它們須作施工前準備的時間。

任何計劃的改變，均應及早通知各有關方

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advance notice or lead time required by the variousagencies, and any changes to the programme should betransmitted to all parties without delay. Whereverpossible, a set of drawings giving details of all work tobe carried out by others should be kept on site forreference.

13.6 RECLAMATIONS

13.6.1 Sequence of Reclamation

Where reclamation is being carried out at the sametime as seawall construction, regular seabed surveysshould be carried out to ensure that no mud wavesaffect the seawall under construction. In general, nofilling should be carried out within 100 m of anuncompleted seawall. For a rubble or concrete blockseawall with rubble foundation, it is usual to form abund, using selected granular material where possible,along the line of and immediately behind the seawall,after completion of block setting and placement offilter material. Such a bund assists with stabilising theseawall and its foundation, reducing the possibility ofmud waves adversely affecting the seawall stability, andhelps to induce initial settlement before continuation ofthe seawall.

13.6.2 Precautions to Be Taken During Reclamation

During reclamation, care should be taken to checkfor existing outfalls, intakes and drains along the lines ofexisting shorelines, particularly at low tide. Any outfalls,intakes or drains which do not appear on thereclamation construction drawings should be recordedimmediately and investigated with the appropriateauthority; temporary channels should be provided asnecessary across the reclamation as a short termmeasure to avoid any delays.

Care should also be taken to minimise dustgenerated by trucks whilst inside the reclamation site.This can be achieved by providing water lorries toregularly water the access roads on the site. Wheelwashing facilities should also be provided at exits to

面。由其他部門或機構進行的所有工程圖

樣，均應保存在工地內，以供參考。

1 3 . 6 填海工程

1 3 . 6 . 1 回填程序

若回填與海堤工程同時進行時，應定

期作海底測量，以確保施工時海堤不受泥

波影響。通常不應在未完工的海堤 1 0 0米

範圍內進行回填。對於堆石海堤或有堆石

地基的混凝土方塊海堤，當安放塊體和鋪

放過濾物料完成後，通常會在海堤後建一

堤壆，材料則盡量選用挑選粒狀物料。這

堤壆可加強海堤及地基的穩定性，減少泥

波影響海堤穩定的可能，也在海堤工程繼

續進行前，加速其初始沉降。

1 3 . 6 . 2 填海時的注意事項

在進行填海工程時，應特別在低潮期

間，沿海岸線檢查原有的排水口、進水口

和水管。圖則上未有註明的排水口、進水

口和水管，均須立即記錄下來，並向有關

當局查明。有需要時，應在填海區上設置

臨時排水渠道，此等臨時措施，可避免工

程延誤。

應注意減少填海工地內由運泥車引起

的灰塵，可用灑水車定期噴灑進出工地的

道路。為避免運泥車將泥沙帶至公共道

路，亦應在出口處備有車輪清洗設備。

138

ensure that dumping trucks do not take out anddeposit mud onto public roads.

13.7 UNDERWATER BLASTING

Requirements for blasting trials, blasting in general,and submissions of particulars of the proposedblasting procedures are given in Section 6 of the GS.Where underwater blasting is envisaged, additionalrequirements should be included in the ParticularSpecification.

The following aspects require special attention :

(a) Underwater blasting can only be carried out by adiver who possesses a valid Mine BlastingCertificate issued by the Commissioner ofMines.

(b) All vessels within 150 m of the blast area shouldbe cleared before the start of blastingoperations.

(c) Requirements concerning the possession and useof explosives are included in the DangerousGoods Ordinance and subsidiary legislation.

(d) Adequate prior notice should be given to theDirector of Marine before any underwaterblasting is carried out.

(e) When explosives are being transported by seaand when underwater blasting operations areunder way, signals should be displayed asprescribed by the Director of Marine.

13.8 MATERIAL INSPECTION AND TESTING

13.8.1 General

This Section gives guidance on inspection andtesting of materials and should be read in conjunctionwith the requirements given in the various sections of

1 3 . 7 水底爆破

《G S》第 6節載有爆破試驗、爆破一

般注意事項，以及呈交擬定爆破程序細則

等規定。若預計須進行水底爆破，特別規

格明細表應加設附加規定。

以下各項須特別注意﹕

( a ) 進行水底爆破的潛水員須持有 務

處發出的有效 場燃爆證書。

( b ) 爆破作業開始之前，所有爆破區1 5 0

米範圍內的船隻均須撤離。

(c) 危險品條例和其附屬法例，載有收

藏和使用炸藥的規定。

( d ) 進行任何水底爆破前，應及早通知

海事處。

( e ) 經海路運輸炸藥和進行水底爆破作

業時，應按海事處的要求，顯示應

有信號。

1 3 . 8 材料檢查和試驗

1 3 . 8 . 1 概述

本節載有檢查和試驗材料方面的指

引，閱讀時應同時參考《G S》的規定。

本節只論及與海事工程直接有關，及一般

專用於海事工程的材料。海事工程使用的

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the GS. Only materials which are directly related to,and generally peculiar to, marine works are covered.The inspection and testing of materials such asconcrete, steel reinforcement and structural steelworkused in marine works should be no different from thatfor the same materials used in general civil engineeringworks, and are therefore not covered.

13.8.2 Marine Fill

The sampling and testing of marine fill material iscovered in Section 21 of the GS; particle sizedistributions for samples taken from the proposedsource of supply are required before any source isapproved, and regular checks on the sand content ofsamples should be made before deposition on site.Regular checks should also be made that the material iscoming from an approved source.

It should be noted that weathered granite from landsources can be used as an alternative to sand in thefoundations of seawalls and breakwaters. Referencemay be made to Lo (1980).

13.8.3 Rock Fill

No particular requirements for sampling and testingrock fill are included in Section 26 of the GS.Different types of rock fill should be checked regularlyfor compliance with the relevant clauses of Section 21of the GS by visual inspection, preferably at stockpilesbefore loading onto barges for dumping at site. Toassist with these visual inspections, specimens of piecesof rock complying with the upper and lower specifiedbounds for size and mass should be kept available forcomparison. In extreme circumstances, particularlywhen there is major disagreement with a contractor, itmay be necessary to carry out a full scale check on thematerial on site before compliance with thespecification can be assured.

混凝土、鋼筋和結構鋼等材料的檢查和試

驗，與一般土木工程相同，因此本節不予

論述。

1 3 . 8 . 2 海相填料

《G S》第 2 1節論述了海相填料的取樣

和試驗。批准材料來源之前，須實地取樣

進行粒徑分析試驗；並在現場拋填之前，

經常取樣檢驗含沙率，同時也應定期檢

核，確保材料來自已批准的來源。

源自陸上的風化花崗岩可用來代替海

堤和防波堤基床中的砂，這方面可參考

L o ( 1 9 8 0 )。

1 3 . 8 . 3 石填料

《G S》第 2 6節沒有為石填料的取樣和

試驗加上特別規定。因此，可按《G S》

第 2 1節中條款，定期為不同種類的石填料

進行目測檢驗。這些目測，應盡量在填料

裝入躉船之前進行。同時，為便於目測，

應存放合乎指定規格上限和下限的石塊

樣本，以供比較。在極端情況下，特別是

與承建商有重大分歧時，有可能須全面檢

查存放在工地的物料，以確定其符合規

格。

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13.8.4 Rock Armour

Requirements for laboratory testing and fieldchecking of rock armour are covered in Section 21 ofthe GS. In general, it is not considered necessary forlaboratory testing to be carried out where rock armourconsists of sound granite. Field checking for mass neednormally only be carried out by visual comparison withthe specimen samples of the upper and lower boundsfor each rock armour type covered in Section 21 of theGS. The 'dropping test' described in Section 21 of theGS should be used as a field check for all rock types.

13.8.5 Timber for Fenders

The sampling and laboratory testing of timber forfenders are covered in Section 21 of the GS. Where thethree pieces of timber selected for preparation of testspecimens are not taken from a supply of timberalready delivered to site, additional specimens fromeach piece should be taken at the time of preparationof the test specimens for future visual comparison withthe timber actually delivered to site and purported tobe from the same supply. All timber delivered to siteshould be checked for the marking required by forTropical Hardwoods Graded for Structural Use inBS 5756 (BSI, 1980) to identify each piece as visuallystress graded hardwood. In addition to the abovechecking, every piece should be inspected for majordefects including knots, fissures, resin pockets, insectholes and fungal decay, before use on site. Any majordefects should be checked against the requirements ofBS 5756.

13.8.6 Rubber Fenders

Requirements for testing and certification of rubberfenders are covered in Section 21 of the GS. Ondelivery to site and before incorporation in the works,each rubber fender should be inspected for defectssuch as surface inclusions, pores and cracks.

1 3 . 8 . 4 護面塊石

《G S》第 2 1節載有護面塊石實驗室試

驗和實地檢查的規定。屬於堅硬的花崗岩

的護面塊石，通常不需實驗室試驗。檢查

《G S》第 2 1節中提到的各種類型護面塊

石的重量時，一般只需在現場用目測，與

符合規格上限和下限的塊石樣本比較。各

種岩石的實地檢查，均可應用《G S》第

2 1節描述的「撞擊試驗」進行。

1 3 . 8 . 5 護木

《G S》第 2 1節載有護木取樣和實驗室

試驗的規定。當用作試件的三塊木料，並

非取自已運往工地的材料時，應在試驗時

從每塊試件中另外截取一段，以供日後與

運至工地，聲稱來自同一貨源的木料，進

行目測比較。應按《B S 5 7 5 6》( B S I , 1 9 8 0 )

對結構用熱帶硬木的規定，檢查所有運至

工地的木料，確定其是否達到目測應力級

硬木應有的質量標準。除上述檢驗以外，

每塊木料在工地使用前，均須經檢查，以

確定其沒有嚴重缺陷，如節疤、裂縫、樹

脂囊、蟲洞及真菌朽壞等。若發現任何嚴

重缺陷，便應參照《B S 5 7 5 6》的規定檢

查。

1 3 . 8 . 6 橡膠護舷

《G S》第 2 1節載有橡膠護舷的試驗與

鑒定的規定。每塊運至工地的橡膠護舷在

安裝於結構之前，應先檢查其有無缺陷，

如表面雜質、孔隙和裂縫等。

141

13.9 COMPLETION OF WORKS

13.9.1 General

This Section gives comments and guidance oncertain aspects related to the completion of works,covering the issue of completion certificates and thepreparation of as-constructed drawings. Only mattersparticularly related to marine works are considered.

13.9.2 Completion Certificates

For concrete blockwork seawall contracts, it iscommon for the construction of the coping and thepointing of the granite facing, and in somecircumstances the installation of bollards, fenders andother fittings, to be carried out in the maintenanceperiod; the works can therefore be generallyconsidered to be substantially complete without theseitems. When considering the possibility of issuing apartial completion certificate for a section of seawallnot immediately required for permanent occupation oruse, the following should normally apply :

(a) The seawall section should be substantiallycompleted, i.e. complete except for coping,pointing and fittings as appropriate.

(b) The length of the section should be not less thanone standard panel length, which is about 24metres.

(c) The land formed behind the section of seawallshould be capable of being put to the use forwhich it is intended.

13.9.3 As-constructed Drawings

As-constructed drawings should be prepared andsigned by the engineer for the contract. In addition tochecking the drawings before signature, the engineershould ensure that all relevant information related tothe use and maintenance of the works is extracted from

1 3 . 9 工程竣工

1 3 . 9 . 1 概述

本章論述與工程竣工有關的一些要

點，亦為此提供指引，其中包括簽發竣工

證書和繪製工程竣工圖。本章只論述與海

事工程有直接關係的問題。

1 3 . 9 . 2 竣工證書

興建混凝土方塊海堤的工程，一般會

延至保養期內才建造牆帽和花崗岩護面

的勾縫，在一些情況下，甚至繫船柱、護

舷和其他裝置，也同樣會留待保養期安

裝，因此，即使這些細項尚未完成，工程

亦可算是基本竣工。當準備發出一段無須

被即時佔用的海堤的局部竣工證書時，通

常應考慮以下幾點﹕

( a ) 該段海堤基本上已完成（牆帽、勾

縫和裝置等除外）。

( b ) 該段海堤不短於一個標準節間長

度，此長度約為 2 4米。

(c) 與該段海堤相鄰的土地，已填築完

成，並能按計劃使用。

1 3 . 9 . 3 工程竣工圖

工程竣工圖，應由負責該合約的工程

師繪製，並在圖則上簽署。簽署前，除檢

查竣工圖外，工程師還應確定一切有關該

工程的使用和保養資料，已從設計計算書

摘錄出來，並以說明或其他適當方式，載

於整體安排圖或其他竣工圖內。以下各項

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the design calculations and incorporated, by way ofnotes or otherwise, into the general arrangement andother as-constructed drawings, as appropriate. Suchinformation should include, but should not necessarilybe limited to :

(a) details of design loadings, in particular live loadsand any vessel design characteristics,

(b) safe working loads for bollards, cranes andother equipment,

(c) corrosion allowances with design lives for anyexposed steel members, and

(d) any special inspection or maintenancerequirements.

Pile record drawings should be included. Theseshould give full details, including pile types, toe levels,sizes, hammer type, final sets and any load testingresults.

Sounding survey results, before and afterconstruction, should be included where appropriate.Foundation trench dredging drawings should beamended to suit, where the actual final dredged profilediffers from that shown on the original constructiondrawings.

As-constructed drawings for reclamations shouldgive final levels, and the outlines of any special dumpingareas such as rock dumps. Temporary drains shouldbe included where these still remain at the date ofpreparation of the as-constructed drawings.

It should be noted that as-constructed drawings areintended to provide a true and accurate record of theworks as completed, for use by the client or user andthe maintenance authority, and for possible later usewhen planning or undertaking modification, extensionor demolition work. As such, the as-constructeddrawings need not necessarily exactly correspond tothe drawings used for payment purposes, particularlywhere different methods of construction from thoseshown on the tender drawings have been proposed bythe contractor and accepted, with payment being basedon the original tender details.

應作為這些資料的一部分﹕

( a ) 設計荷載，特別是活荷載和船舶設

計特性的詳細資料，

( b ) 繫船柱、起重機和其他設備的安全

工作荷載，

(c) 外露鋼構件在設計使用期的容許銹

蝕量，及

( d ) 特殊檢查或保養要求。

竣工圖應包括打樁記錄圖，圖中應列

出有關的詳細資料，包括樁的類型、樁底

高程、尺寸、打樁錘的類型，最終貫入度

及荷載試驗結果等。

竣工圖亦應包括施工前後的測深結

果。當最後挖成的實測剖面與原施工圖所

示剖面不同時，應修改基坑挖泥圖。

填海工程的竣工圖，應詳載各個特殊

物料傾卸區（如棄石場）的最後高程和範

圍。如果在繪製竣工圖期間，填海區內仍

然有臨時排水渠道，應於圖中表明。

應指出的是，竣工圖應提供真實、準

確的竣工工程記錄，以供委托人，使用者

和保養部門應用，並供將來可能進行改

建、擴建或拆卸時使用。因此，竣工圖不

必與付款用圖則完全相同，特別是當承建

商提出的施工方法與招標圖則不同而又

獲得批准時，付款仍會以原招標詳圖為依

據。

143

144

14. MAINTENANCE

14.1 Maintenance Inspections

14.1.1 Routine Inspections

Regular routine inspections of all piers and landingsshould be carried out. The frequency of inspectiondepends on the importance and vulnerability todamage of the pier or landing. In general, inspectionsof the structures above low water level should becarried out at least twice a year for facilities in the urbanarea, and at least once a year for facilities in the NewTerritories. For heavily used piers and landings in theurban area, it is necessary to carry out inspections of thefendering systems, particularly step-blocks, at least oncea month. The frequency of underwater inspectionsdepends on the availability of divers, weatherconditions and access constraints. The aim should beto keep the period between underwater inspections toabout 12 to 18 months for the urban area and 18 to 24months for the New Territories.

14.1.2 Special Inspections

In addition to regular routine inspections, specialinspections are needed in the following circumstances :

(a) after a severe tropical storm or typhoon(priority should be given initially to inspection ofthe fendering systems),

(b) after an accident such as a vessel collision,

(c) when a complaint or notice about any damage isreceived, and

(d) after completion of repairs.

14.1.3 Inspection Procedures

Wherever possible, all above-water inspectionsshould be arranged to be carried out at low tide. The

1 4 . 保養

1 4 . 1 維護性檢查

1 4 . 1 . 1 常規檢查

所有碼頭和登岸平台均應定期進行例

行檢查，檢查頻率取決於它們的重要性和

是否易於損壞。位於巿區，而在低水位以

上的結構，通常應每年至少檢查兩次，位

於新界的結構，則至少每年一次。巿區內

使用率高的碼頭和登岸平台上的護舷設

備，特別是踏木塊，至少應每月檢查一

次。水下部分檢查的頻率，取決於潛水

員、天氣情況和是否易於到達。在巿區的

指標，應訂為相隔約 1 2至 1 8個月，而在

新界，則為 1 8至 2 4個月。

1 4 . 1 . 2 特別檢查

除定期進行常規檢查外，還應在下列

情況下進行特別檢查：

( a ) 風暴吹襲後 （應首先檢查護舷 設

備），

( b ) 如撞船等意外事故之後，

(c) 接到損壞的投訴和通知，及

( d ) 維修工程完竣後。

1 4 . 1 . 3 檢查程序

在可能情況下，應將水上檢查安排在

低潮期間進行。檢查的範圍，應包括所有

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above-water inspections should include all structuralmembers, fendering systems, landings, steps, handrails,pier light posts and mooring facilities. Underwaterinspections should include, where possible, all piles,pedestals and foundations, and particular attentionshould be paid to possible undermining of pedestalbases and toe blocks at shallow depths, i.e. higher thanabout -3 mCD. In many cases, it will not be possibleor practical to carry out an underwater inspection of allpiles and pedestals due to time and access constraints.In this situation, typical piles and pedestals at differentparts of the structure should be inspected, and thisshould be noted on the inspection report. Whencarrying out underwater inspections, marine growthgenerally should not be removed from piles andpedestals, except locally when investigating possibledefects or voids.

Where any inspection identifies areas ofdeterioration or damage, the inspection report shouldbe accompanied by sketches showing the location ofthe deterioration or damage and the extent of therepair required.

14.2 Dredging

14.2.1 General

Many aspects covered in Section 13.2, and inparticular those concerning navigation dredging, arealso relevant when considering maintenance dredging.Section 13.2 should be consulted for basic guidance onsuch matters as the checking of land marks and tidegauges, the keeping of daily records, reduction factorsfor interim surveys, material sampling and theinterpretation of echo sounder results.

14.2.2 Sampling and Surveys

Normally, the sand content of samples need notnormally be obtained for maintenance dredging.Because the thickness of material required to beremoved by dredging is generally less than one to two

結構構件、護舷設備、登岸平台、階梯、

欄桿、碼頭燈柱及繫船設施。水下檢查應

盡可能包括所有樁、支座和地基，並應特

別注意在淺水區，即高於 - 3 m C D的支座

和堤腳塊體，底部有否淘空。由於時間和

通道的限制，在水底檢查所有的樁和支

座，很多時是不可能或不設實際的。這

時，只須檢查在結構各不同部分內，有代

表性的樁和支座，這些資料應在檢查報告

中說明。進行水下檢查時，除非是要查證

樁和支座的局部地方是否已損壞或有孔

隙，否則一般不應將其上的海洋附殖物除

去。

若檢查時發現有正在變壞或已損毀的

地方，檢查報告應附有簡圖，標明變壞或

損毀的位置和需要維修的範圍。

1 4 . 2 挖泥

1 4 . 2 . 1 概述

第 1 3 . 2節論述的許多要點，特別是有

關航道開挖的問題，都與維護性疏浚有

關。岸標和潮位計的檢查、日常記錄、階

段性測量檢定的折減系數、材料取樣和聲

納測深結果的整理分析等，可參閱第1 3 . 2

節內的一般指引。

1 4 . 2 . 2 取樣與測量

維護性疏浚，通常不必取樣試驗含沙

率。測量時因為需要挖掉的泥沙厚度一般

少於 1至 2米，所以很少遇到懸浮泥漿影響

聲納測深結果的問題；但使用聲納測深

146

metres, problems are not usually experienced withmud in suspension affecting echo sounder results;however, checks using chain sounding should be madewhere echo sounding is used. In certain cases, vesselcongestion, access problems or the shape of the area tobe dredged will mean that chain sounding in place ofecho sounding will need to be used in any event. Formaintenance dredging in rivers and nullahs, currentpractice is to use chain sounding, with the leadmodified with a steel disc because of the very softdeposits; echo sounding is sometimes used for checksurveys at higher tides and over deeper sections, butnot for payment purposes.

14.2.3 Maintenance Dredging Adjacent to Structures

Subject to the need to ensure no undermining ofexisting adjacent structures, maintenance dredgingshould preferably be carried out to a level deeper thanthe minimum depth required for navigation or otherpurposes, to allow for future siltation. Whereverpossible, subject to the above limitations, there shouldbe no need for future maintenance dredging for at leasttwo years, and preferably three to five years, aftercompletion.

For maintenance dredging immediately adjacent toexisting structures, particularly pumphouse intakes andslipways, and where it is necessary to fully removedeposits from the tops of toe blocks, bermstones, rockfill or rock armour structures, grab dredgers cannot beused. In these circumstances, it is usually necessary tocarry out initial removal of the material to a moreaccessible location by air-lift equipment for laterremoval by grab dredger, or to an adjacent locationwhere it is not necessary to remove the material due topartial dispersal or the presence of low spots.

14.2.4 Maintenance Dredging of Rivers and Nullahs

Maintenance dredging of rivers and nullahs may behampered by the following difficulties :

時，仍須用鏈測深檢驗。在某些時候，因

挖泥區船舶擁擠、進出困難或受挖泥區域

的形狀限制，只能使用測深鏈。對於河流

和水道的維護性疏浚，因沉積物的密度較

低，所以現行的辦法是使用改成鋼盤鉛錘

的測深鏈。有時會利用聲納測深，檢核潮

位較高時在較深水域的測深結果，但其結

果不會用作計算工程費用的依據。

1 4 . 2 . 3 結構附近的維護性疏浚

除因為要避免將附近結構的底部淘空

外，維護性疏浚的深度，應盡量超過通航

或其他用途所要求的最小深度，以容納將

來的淤積。在可能情況下，應做到竣工後

至少兩年，最好三至五年內，不用再進行

維護性疏浚。

若要在現有結構，特別是泵房進水口

和船排附近進行維護性疏浚，或有需要在

堤腳塊體、護腳石、填石或塊石護面結構

的頂部清除沉積物，不得使用抓斗式挖泥

船。在這種情況下，通常須把沉積物用壓

縮空氣揚水泵轉移到較容易到達的地

方，然後再用抓斗式挖泥船清理；或將其

移到附近坑窪之處，或一些可令其部分擴

散的地方，這樣便不必再另行清理。

1 4 . 2 . 4 河流與水道的維護性疏浚

河流與水道的維護 性疏浚，可能遇到

下列困難：

147

(a) restricted access for marine plant due to shallowwater and existing bridges with limitedheadroom,

(b) limitations on dredging depths due to highchannel design invert and bank levels,

(c) land access only available at certain locations forremoval of material by land plant,

(d) the fluid nature of deposits, resulting in leakagefrom barges and trucks, and

(e) existing gas pipe and other services within andacross channels, requiring additional control ondredging location and level.

The type of equipment to be used to overcome theabove difficulties should be left to the contractor todevelop. Cutter suction dredgers as well as grabdredgers have been successfully used in the Shing MunRiver, using specifically modified tugs and bargeswithin the river channel itself.

Maintenance dredging in fairways, e.g. the NorthernFairway, may require the use of trailer suction dredgers,where the Director of Marine stipulates that stationarydredging plant would be hazardous to shipping andtherefore not permitted.

14.3 Piers and Dolphins

14.3.1 Piles

For precast reinforced and prestressed concretepiles, usually the only sections showing defects andrequiring maintenance are in the tidal and splash zones;for repairs to these sections, reference may be made tothe advice given for concrete pile caps under Section14.3.2, as the work will be of a similar nature.

For uncoated tubular steel piles, corrosion of thesteel should only be ignored when the as-constructeddrawings indicate that the piles have been infilled withreinforced concrete to well below bed level, and thedesign calculations show that the steel is sacrificial and

( a ) 水深和現有橋樑高度對往來船隻的

限制，令海事工程船隻無法接近，

( b ) 因河床及堤岸的設計高程較高，而

造成浚深的限制，

(c) 用陸上設備清除沉積物，卻只有少

數地點可由陸路到達，

( d ) 液化的沉積物，由躉船和貨車洩

漏，及

( e ) 因航道內有煤氣管道或其他設施，

限制疏浚工程的高程。

應由承建商安排設備，來克服以上的

困難。鉸吸式和抓斗式挖泥船，與經特別

改裝的拖船和躉船等，曾成功地在城門河

使用。

非自航式挖泥設備，在如北航道的主

航道進行維護性疏浚時，可能會引致船隻

事故發生，因此，海事處不准在這些區域

使用此類設備，這時，可能須要使用耙吸

式挖泥船。

1 4 . 3 碼頭和船墩

1 4 . 3 . 1 樁

預製鋼筋混凝土樁和預應力鋼筋混凝

土樁，通常僅在潮位變動和浪濺區，會出

現缺陷和須要維修； 對 此，可參考第

1 4 . 3 . 2節關於混凝土樁帽的建議，因為這

兩類維修工程的性質相似。

若鋼管樁未加塗層，則只有當竣工圖

顯示樁內已填入鋼筋混凝土，直到海床以

下足夠深度，而且設計計算書列明，容許

鋼材因銹蝕而完全消耗，並在設計時已將

這因素考慮在內，鋼的銹蝕才可忽略不

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has not been taken into account in the design.

For coated or wrapped tubular steel piles, it shouldbe assumed that the coating or wrapping is essential forthe full protection of the piles, and no loss of steelthickness has been allowed for in the design, unlessevidence to the contrary is available from the as-constructed drawings or the design calculations.

Where it is necessary for the corrosion rate for asteel pile to be checked, it is recommended that thisshould be carried out by a suitably qualified companyusing specialist equipment. For each pile, a sufficientnumber of measurements should be made at eachlevel, to ensure confidence in the assessed maximum,minimum and average thicknesses. For uncoated steelpiles, where the design calculations allow a certainyearly corrosion loss, it is recommended that the firstcorrosion check should be carried out between threeand five years after completion of pile driving.Intervals between subsequent checks will depend onthe losses measured in relation to the designassumptions, but it is suggested that the time betweenchecks should not exceed five years.

Where maintenance work to tubular steel piles isnecessary, because of damage to the existing coating orwrapping, or steel corrosion rate greater than allowedfor in the design calculations, it is suggested thatdiscussions are held with specialist suppliers, andsubcontractors if necessary, before the method andtype of repair is finalised. In all cases, the mostappropriate method and type of repair will depend onthe site conditions, location, type and extent of thedamage. The application of a coal tar reinstatementepoxy, which can be applied underwater by glove, maybe economical for small areas, and a proprietaryunderwater wrapping system for larger areas. In allcases, surface preparation must be in accordance withthe material supplier's recommendations, and theremay be a need to use a specialist subcontractor.

Repairs to timber and steel H-section fender pilesare not usually practical or economical, and it is

理。

鋼管樁若有塗層和包封，便應假定它

們對樁的全面保護至關重要，而且設計時

並不容許鋼料耗蝕；若竣工圖和設計計算

書中有相反的說明，則屬例外。

如須檢測鋼樁的銹蝕率，建議由具備

適當資格的公司採用專門設備進行。檢測

時，在每根樁的各個不同高程，都應搜集

充足數據，以確保估計的最大、最小和平

均厚度與實際情況相符。若鋼樁未有塗

層，而設計計算書又容許一定的年銹蝕損

失，建議在打樁完成後的三至五年間便進

行第一次銹蝕檢測。以後的檢測時間，取

決於設計時假設的損失與測量結果的差

別，但建議每次檢測相距不應超過五年。

凡因鋼管樁上原有塗層和包封損壞，

或鋼材銹蝕超過了設計計算書中容許的

銹蝕速度，而須進行維修，建議在確定維

修方法和形式之前，與專門供應商，甚或

分包承建商商討。最適當的維修方法和形

式，其實取決於當時結構所處環境、位

置、損壞程度及其類型。可用手套在水中

塗上的煤焦油環氧樹脂，在小範圍使用可

能比較經濟；專利的水下包封系統，則適

用於大面積範圍。任何情況下，表面處理

均應遵照材料供應商的建議，需要時可請

專門分包商處理。

一般情況下，維修木護舷樁和H型護舷

鋼樁，既不實際也不經濟，因此慣常是會

149

common to replace damaged piles with new ones.Where full replacement of steel piles is difficult orimpossible due to time or headroom constraints,temporary repairs may be made for corroded ordamaged sections above low water level by cutting offthe section in question and welding or splicing on areplacement section at low tide.

For cathodic protection systems, it isrecommended that all inspection, monitoring andmaintenance work should be carried out by a suitablyqualified company which specialises in such work, withall maintenance work being carried out in accordancewith BS 7361 (BSI, 1991c). It should be noted thatcathodic protection is usually considered to be fullyeffective up to about the mid-tide level, provided thesystem is well designed and maintained.

14.3.2 Decks

For reinforced concrete decks, most maintenancework requires the treatment of defects which haveresulted in reinforcement corrosion. Such corrosion isusually apparent first as rust staining at cracks, followedin due course by concrete spalling, exposing corrodedreinforcement. It is important to try to distinguishbetween different types of cracks and their causes, andto determine, where possible, the reasons for anyreinforcement corrosion. Certain types of cracks, forexample those caused by structural or temperaturemovements and shrinkage, may result in reinforcementcorrosion, while other cracks may be caused byexpansion of reinforcement as it corrodes.

For the majority of reinforced concrete deckstructures covered by this Chapter, the main problemswith reinforcement corrosion occur about 15 to 25years after construction, in the upper tidal and splashzones, and appear to be due to chloride movementfrom the surfaces of the pile caps, beam sides andsoffits, and slab soffits to the concrete immediatelysurrounding the reinforcing bars. Corrosion problemsare usually at first only apparent in areas with higher

用新樁更換壞樁。凡因時間或工作空間限

制而不能或難以將全部鋼樁更換，可趁在

低潮時切斷低水位以上銹蝕或損壞的部

分，然後透過焊接或插接與替代的鋼材連

接，作臨時維修。

若使用陰極防蝕系統，建議所有檢

查、監測和保養工作均由有適當資格的專

業公司進行，而所有保養工作均應遵照

《B S 7 3 6 1》 ( B S I , 1 9 9 1 c ) 的規定進行。

如果陰極防蝕系統設計和保養良好，一般

都能夠在中潮位以下發揮效用。

1 4 . 3 . 2 碼頭面板

維修鋼筋混凝土面板的主要工作，是

處理鋼筋銹蝕造成的損壞。通常，這些銹

蝕最初被發覺時，是裂縫表面出現銹斑，

隨後混凝土會剝落，並露出銹蝕鋼筋。這

時，應盡可能辨明裂縫的種類和成因，和

確定鋼筋銹蝕的原因。有時結構的移位或

冷縮熱脹等因素，會產生裂縫而導致鋼筋

銹蝕，而有時銹蝕亦會使鋼筋膨脹而產生

裂縫。

本章提及的大部分鋼筋混凝土面板結

構，都會在施工後約 1 5至 2 5年間在高潮

位和浪濺區出現嚴重的鋼筋銹蝕，而且似

乎都是由於氯化物從樁帽表面、橫樑側面

和底面及面板底面，滲透至鋼筋旁的混凝

土。銹蝕問題通常會在混凝土滲透性較高

和保護層較薄的地方首先出現。

150

concrete permeability or lower cover.

Repairs should be carried out as soon as cracks withrust stains are detected, in order to reduce thepossibility of significant steel loss from the reinforcingbars due to corrosion. Concrete spalling can indicatethat significant steel loss has already taken place, inwhich case costly repairs will be necessary. Forsusceptible areas, it is preferable for chloridepenetration to be monitored, and protective coatingsapplied where necessary.

Cracks can be repaired temporarily by breaking outto expose the affected reinforcing bars, removingloose rust, and patching with epoxy mortar orconcrete, after cleaning and priming as recommendedby the manufacturer. Such repairs will usually lastseveral years until further cracks develop, usually at theedges of the previous repair. More permanent repairs,which can usually last for at least five years andsometimes up to eight or ten years, can be carried outby :

(a) breaking out all concrete adjacent to the affectedbars, including behind the bars,

(b) removing all loose rust,

(c) scabbling the adjacent surfaces,

(d) fixing a galvanised wire mesh, and

(e) guniting in layers using a 1 : 3 cement/sand mixover the full affected area.

Maintenance problems with reinforced concretepile caps and beams in the lower tide and submergedzones do not usually relate to normal reinforcementcorrosion, due possibly to the reduced supply ofoxygen and protection by marine growth. Within thesezones, problems are more likely to be due to poorlycompacted concrete or the use of concrete placed bytremie, combined with congested reinforcement. Theuse of concrete placed by tremie in low level pile capsappears to be a major cause of defects, and oftenresults in effective wash-out of the concreteconstituents over periods of months or years,

為減少銹蝕對鋼筋的損壞，一旦發現

混凝土出現帶有銹斑的裂紋，便應立即進

行維修。待至混凝土剝落時，鋼銹蝕損失

已經相當嚴重，此時進行維修會相當昂

貴。在易受破壞的地方應監測氯化物的滲

透情況，如有需要則加防護塗料。

臨時維修裂縫的方法，是先除去鋼筋

旁的混凝土，盡可能清除鐵銹，再按生產

商的建議進行清洗和塗底，最後用環氧樹

脂灰漿或混凝土修補。這種維修方法的效

用一般可維持數年，直至裂縫再出現，這

些裂縫通常出現在曾經維修部分的邊

緣。有效期較長的維修（至少維持五年或

可能達到八至十年），可用下列方法進

行：

( a ) 銹蝕鋼筋周圍的混凝土全部除去，

( b ) 清除所有鐵銹，

(c) 鑿花相鄰的混凝土表面，

( d ) 安裝鍍鋅鋼絲網，及

( e ) 在整個受影響部分，鋪上 1： 3水泥

/砂噴漿層。

在低潮位和水下部分的鋼筋混凝土樁

帽和樑，通常沒有常見的鋼筋銹蝕問題，

這可能由於只有較少的氧氣供應，和有海

洋附殖物保護。在這些部分出現的銹蝕問

題，多數是因為混凝土搗壓不足，或是因

用了豎管澆灌混凝土，再加上鋼筋過密而

產生。用豎管澆注混凝土往位於低水位的

樁帽，可能是導致缺陷出現的主要原因。

常有的情況是在一段時間後，混凝土成分

被大量 蝕掉，特別是當流急浪大，以及

駛過或靠泊船隻引起湍流時， 蝕更加嚴

重。

151

particularly when combined with high currents, wavesand turbulence from passing or berthing vessels.

Concrete repairs within the lower tide andsubmerged zones are generally difficult, and aneffective life of only about five to eight years should beexpected. The use of epoxy mortar and gunite isusually not possible, and the usual method of repair isto provide an additional collar of concrete to cover thearea of defective concrete or washout. Care must betaken to remove all marine growth and or loosedefective concrete by hand tools, air jet or water jet asappropriate, with work being carried out at low tide orby diver. Any exposed reinforcement must be cleanedand supplemented as necessary. Adjacent concretesurfaces should be scabbled, and dowel bars providedto key the new concrete collar, which should benominally reinforced, to the existing concrete.Concrete can either be placed by tremie or 'in the dry'using extended watertight shutters, depending on thelocation, space and access constraints. If neither of theabove methods of placing is considered suitable, theuse of 'underwater' concrete, placed 'in the wet', using aproprietary admixture to increase cohesion, may beattempted; in this case, the manufacturer's instructionsmust be followed, and site trials must be carried out.

For comments on repairs to steel members wherethese comprise part of a deck, reference can be madeto Section 14.3.1 for below-deck work similar innature to that required for steel H-section fender piles,and Section 14.3.5 for work generally above tide level.

14.3.3 Fendering Systems

Repairs to normal timber fendering systems relategenerally to loose, worn or missing step blocks,capping pieces and fenders. Repair work is usuallyrelatively straightforward. Spikes, bolts and other steelfixtures and fittings should be replaced as a matter ofcourse during repair work, where corrosion has causeda significant loss in section. In general, timber fendersshould be replaced before the reduction in thickness at

在低潮位和水下部分維修混凝土，一

般都比較困難，預計有效期只有五至八

年。一般情況下，不能使用環氧樹脂灰漿

和噴漿，慣常的維修方法，是澆注一混凝

土環，包住有缺陷的混凝土或被 蝕的部

分。如趁低潮維修或由潛水員在水下維

修，必須小心用手工具、利用噴射氣流或

水流，清除海洋附殖物和有缺陷的混凝

土。所有外露的鋼筋，都必須清理和增

補。相鄰的混凝土表面也應鑿花，並加上

榫栓將其與所注的混凝土環牢固地連結

。混凝土環應加上適量鋼筋。混凝土可

用豎管澆注，也可視乎位置、空間和通道

的困難程度，而使用伸延擋水板進行「乾

式」澆灌。如認為以上兩種方法都不適

當，可試用含有增加凝聚力的添加劑的混

凝土在「水下」澆灌。此時，必須遵照製

造商指示，並進行實地試驗。

碼頭面板的鋼構件須要維修時，若構

件在面板以下，而維修工作的性質又與H

型鋼護舷樁所需的類似，可參考第1 4 . 3 . 1

節的說明，若構件在潮位以上的地方，可

參考第 1 4 . 3 . 5節。

1 4 . 3 . 3 護舷設備

維修常用的木質護舷設備時，通常是

針對已鬆脫、磨損或丟失的踏木塊、壓簷

木和護木，這類維修較為簡單。若發現長

釘、螺栓以及其他鋼附件和配件嚴重銹

蝕，維修時就應更換。一般來說，在任何

剖面的厚度磨損掉 2 0﹪以上時，護木便應

更換。應該指出的是，這磨蝕了的厚度，

幾乎相當於剖面模量或強度減少了 5 0

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any section due to wear exceeds 20%. It should benoted that such a reduction in thickness is equivalent toa section modulus or strength loss of almost 50%.When arranging for repair work, the opportunityshould be taken to carry out minor improvements todesign details, for example fixing, stiffening andbracing arrangements. For comments on themaintenance of timber and H-section steel piles, seeSection 14.3.1.

Routine maintenance for fendering systemsconsisting of rubber cell fenders with steel frontalframes will normally be limited to rotation andoccasional replacement of the nylon and polyethylenewearing pads. Touching up or complete repainting ofthe steel frontal frames should be carried out whendamage to, or significant deterioration of, the originalcoal tar epoxy paint is detected. Removal of the frontalframes will be required for most touch up andrepainting work; immediate replacement of the frontalframe with a spare frame or frame moved from a lesscritical location will usually be necessary. For touch upand repainting work, surface preparation should becarried out strictly in accordance with themanufacturer's recommendations. A minimum dryfilm thickness of 350 µm for repair work using coal tarepoxy paint is recommended.

Damage to rubber cell fenders, rubber arch fendersand cylindrical rubber fenders will normally be limitedto misuse or accident conditions. To avoid delays inreplacing such fenders due to delivery time, a sufficientstock of spare fenders of each type and size should bekept ready for immediate use.

Sway and sag chains for cell fender frontal framesand support chains for cylindrical fenders, togetherwith their shackles, are usually of galvanised steel.Corrosion of the chains and shackles can normally beaccepted until an effective reduction in diameter ofabout 10% at any section has occurred; in this case thefull length of chain with shackles should be replaced.Such a reduction in diameter corresponds to a tensionstrength loss of almost 20%.

﹪。在安排維修工作時，應同時改善設計

的細節部分，例如固定、支撐和加勁的裝

置等。有關木護舷樁和H型鋼護舷樁的維

修，可參考第 1 4 . 3 . 1節。

若護舷系統由鼓形橡膠護舷和防撞鋼

構架組成，則一般的例行維修只須調正或

更換尼龍和聚乙烯耐磨墊。當發現防撞鋼

構架原煤焦油環氧樹脂塗層損壞或嚴重

退化時，應進行修補或全部重塗。為徹底

修整和重塗，應將構架拆除，暫時使用備

用構架，或移用次要位置的構架臨時替

代。修整和重新塗層的表面處理工作，應

嚴格依照製造商的建議。使用煤焦油環氧

樹脂塗料維修時，建議最小乾膜厚度為

3 5 0微米。

鼓形、拱形和圓形橡膠護舷的損壞，

大多由誤用和意外引起，為避免因供應商

不能及時送貨，而延誤更換這些護舷的工

作，應有各種類型和規格的護舷配件備

用。

鼓形護舷鋼構架的固定鏈、圓形護舷

的支承鏈以及卡環，一般均為鍍鋅鋼。如

果支承鏈和卡環的銹蝕使直徑減少不超

過 1 0﹪，還可繼續使用；如直徑減少超過

1 0﹪，相當於拉力強度損失近2 0﹪，則

須要更換整條支承鏈和卡環。

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U-anchors for the above chains are usually also ofgalvanised steel. Because the loads on such anchors areusually a combination of tension and bending, andreplacement of the anchors, which are usually cast in, isparticularly difficult, it is recommended that anycorrosion is treated as soon as it is detected. Corrosionwill normally first be apparent at the junction betweenthe galvanised steel and the concrete support member,and treatment will be far easier and more effective ifcarried out before serious pitting and concrete spallingoccurs. Treatment with coal tar epoxy paint to aminimum dry film thickness of 350 µm is suggested,after surface preparation strictly in accordance with themanufacturer's recommendations.

14.3.4 Steps and Landings

Repairs to concrete steps and landings are relativelycommon due to heavy use and the adverse tidallocation; these relate mainly to :

(a) damage to edges, due to step block/cappingstrip impact, and impact from heavy goodsbeing carried to or from a vessel,

(b) regular renovation or replacement of therough-cast finish due to wear, and, in the longerterm, and

(c) cracks and possible spalling of concrete due toreinforcement corrosion.

Wherever possible, repairs should be carried out insuch a way as to avoid the need for closing more than apart of any steps or landing at any one time. To avoidthe need for complete replacement of any step orlanding, cracks due to reinforcement corrosion shouldbe treated as soon as they are detected. A suggestedmethod of treatment is given in 14.3.2 above.

14.3.5 Miscellaneous Items

Repairs and maintenance to miscellaneous items

上述支承鏈的U型錨栓，通常也由鍍鋅

鋼製成。因為在這種錨栓上的荷載，一般

為拉伸和彎曲荷載的組合，加上它們通常

為預埋，更換非常困難，所以一旦發現銹

蝕，便應立即處理。銹蝕一般首先出現在

鍍鋅鋼和混凝土支承構件之間的接合

處，如在嚴重的孔蝕和混凝土剝落出現之

前處理，則更容易及有效。應嚴格按照生

產商的建議進行表面處理，然後加上用煤

焦油環氧樹脂塗料，建議最小乾膜厚度為

3 5 0微米。

1 4 . 3 . 4 階梯和登岸平台

由於使用率高和潮汐的不利影響，混

凝土階梯和登岸平台須經常維修；工作主

要包括以下幾項：

( a ) 邊緣的損壞，通常因踏木塊和壓簷

木的碰撞，以及裝卸沉重貨物時的

撞擊而引起，

( b ) 定期修整或更新已磨損的粗注面，

及

(c) 較長期的，是在混凝土上因鋼筋銹

蝕引起的裂縫和剝落。

維修時應盡量避免完全封閉階梯和登

岸平台。一旦發現鋼筋銹蝕裂縫，應及時

處理，這樣，便無需更換階梯和登岸平

台。建議的處理方法，載於第1 4 . 3 . 2節。

1 4 . 3 . 5 雜類項目

此節論述雜類項目，如繫船柱、繫船

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such as bollards, mooring eyes, ladders, light posts andhandrails are covered below.

Regular maintenance to standard cast ironconcrete-infilled bollards is not usually necessary, ascorrosion of the cast iron is not normally significant.Maintenance is limited to occasional repainting withbitumen paint to improve appearance where corrosionof the cast iron is noticeable; this is normally limited tobollards on public piers and at heavily used landingsteps within the urban area.

For the older mooring eyes and ladders, whichwere often only of steel treated with bitumen paint,normal practice has been to carry out no routinemaintenance, but to wait until material loss fromcorrosion has become significant and then to replacethe items with new sections. It is recommended that,for the older items, this practice should be continuedbecause of the difficulty in carrying out an effectivepaint treatment to such items after corrosion is wellunderway. As a guide, mooring eyes and laddersshould be replaced when an effective reduction indiameter or thickness of the steel section of about 20%has occurred; replacement items should be ofgalvanised or stainless steel.

For the newer and replacement mooring eyes andladders, which will be of galvanised or stainless steel, itis recommended that regular maintenance coveringtreatment of any detected corrosion is carried out asfor fender chain U-anchors under Section 14.3.3above.

Such treatment is particularly important at thejunction between the steel section and the concrete.Regular maintenance will significantly extend the life ofgalvanised and stainless steel mooring eyes and ladders,and will avoid unsightly rust stains on the adjacentconcrete faces. Heavily corroded mooring eyes cancause additional wear on mooring lines and heavilycorroded ladders can be uncomfortable anddangerous for users.

Light posts and light support steelwork should beregularly treated and repainted to ensure that no

環、爬梯、燈柱和欄桿等的保養與維修。

以混凝土填滿的標準鑄鐵繫船柱，鑄

鐵銹蝕一般並不嚴重，所以通常不需進行

定期維修。保養工作只需以瀝清塗料，重

新塗在發現銹蝕的繫船柱上，以改善外

觀。而且，通常只是在巿區和使用率高的

公用碼頭及登岸台階，才有此需要。

較舊的鋼製繫船環和爬梯，只經瀝青

塗料處理，一般並沒有例行保養，待鋼料

遭嚴重銹蝕後，才用新的構件替換。建議

繼續用這種方法，處理較舊的構件，因為

銹蝕開始之後，便難以進行有效的塗層處

理。繫船環和爬梯的剖面直徑和厚度明顯

減少約 2 0﹪時，便須更換，這些新構件應

以鍍鋅鋼或不銹鋼製造。

較新的或已更換的繫船環和爬梯，應

是鍍鋅鋼或不銹鋼製造的，建議按第

1 4 . 3 . 3節所述保養護舷鏈U型錨栓的方法

進行例行保養，其中包括發現銹蝕時的處

理方法。

這種處理對鋼和混凝土之間的結合處

相當重要。定期保養能延長鍍鋅鋼和不銹

鋼繫船環和爬梯的使用期，並可防止相鄰

混凝土表面出現銹斑。嚴重銹蝕的繫船

環，會加速繫船纜索磨損，而嚴重銹蝕的

爬梯，則會令使用者不舒適和造成危險。

燈柱和航燈支承鋼架，應定期處理和

重新塗層，以防銹蝕發展，亦應保持海事

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corrosion is allowed to develop, and that any colourcode required by the Director of Marine is maintained.The steel structures are usually located above tidalzones and surface preparation followed by repaintingis generally not difficult.

The importance of adequate surface preparationand the need to carry out all work in favourableweather conditions to avoid contamination frommoisture in the air and sea spray cannot beoverstressed.

Steel handrails should be regularly maintained toensure maximum life and to avoid an unsightlyappearance, particularly from rust staining. Unpaintedgalvanised steel sections should be treated with anappropriate paint system whenever corrosion isdetected. Painted galvanised steel sections should berepainted whenever breakdown of the existing paint isdetected and the underlying galvanised finish is visible.Surface preparation in accordance with the paintmanufacturer's recommendations is important,particularly when painting or repainting galvanisedsurfaces. For handrails at lower landings and stepswhich are continuously within the lower tidal andsplash zones, satisfactory surface preparation forpainting or repainting will often not be possible. In thissituation, the only practical solution is to replace anyheavily corroded sections with new stainless steel orgalvanised members, prepainted if possible.

14.4 Blockwork Seawalls

14.4.1 General

Regular routine maintenance to concreteblockwork seawalls of standard design is usually notnecessary. However, repairs to certain parts of theseawall structure, including rubble foundations, outfallblocks, granite facing and coping, can be requiredunder particular circumstances, and these are dealt withbelow. For comments on repairs to fendering systems,steps and landings, bollards and miscellaneoussteelwork items, such as mooring eyes, ladders andhandrails, see Sections 14.3.3, 14.3.4 and 14.3.5.

處規定的顏色代號。這些鋼結構一般設置

在潮位以上，表面處理與重新塗層並不困

難。

這裏，特別要強調優良的表面處理的

重要性，並且所有工序須在良好的天氣下

進行，這樣才能免受空氣中或浪花產生的

水氣影響。

鋼欄桿應定期保養，使其有最長的使

用期和防止銹斑影響外觀。若發現未有塗

層的鍍鋅鋼出現銹蝕，便須用適當塗料處

理。若鍍鋅鋼有塗層，而原有塗層已破

損，使鍍鋅面外露，便應重新塗層。表面

處理，特別是鍍鋅表面的塗層和重新塗

層，必須遵照塗料製造商的建議進行。在

低潮和浪濺區的登岸平台和階梯欄桿，所

處位置較低，塗層和重新塗層所需的表面

處理，往往不可能達到標準。在這種情況

下，唯一實際可行的方法是將銹蝕嚴重的

部分，換上新的不銹鋼或鍍鋅鋼構件，如

有可能，這些構件應預先加上塗層。

1 4 . 4 方塊海堤

1 4 . 4 . 1 概述

使用標準設計的混凝土方塊海堤，一

般無須進行常規保養。但是方塊海堤的某

些部分，包括堆石地基、排水口砌塊、花

崗岩面層和牆帽，在特殊情況下須進行維

修，下文會對此詳細論述。關於護舷系

統、階梯、登岸平台、繫船柱及其他鋼結

構（如繫船環、爬梯和欄桿）的維修，可

參考第 1 4 . 3 . 3節、 1 4 . 3 . 4節和 1 4 . 3 . 5節。

156

14.4.2 Repairs to Rubble Mounds

Damage to rubble mound foundations due tocurrents and wave attack can result in undermining ofbermstones and toe blocks, which in turn can result inloss of fill material from behind the seawall. The firstwarning of such damage will usually be thedevelopment of cracks in the paving behind the seawallcaused by voids forming under the paving. This typeof damage usually only occurs in locations exposed torelatively severe wave attack and where the seawall toeblock level is relatively high, generally above -2.0 mCD.Undermining is particularly likely to occur with sectionsof older seawalls which have been founded on rockoutcrops where the normal standard bermstone/toeblock detail has not been used. A diving inspection willconfirm the presence of voids at the interface of theconcrete blocks and rubble mound foundation whenundermining is suspected; there will also usually beevidence of fill material in the region in front of thewall.

It is important that repair work to any underminingis carried out as soon as it is detected to avoidadditional loss of fill material, possible completecollapse of the paving behind the seawall, and possiblesettlement, rotation or even collapse of the seawallitself. The method of repair will depend on thecircumstances in each case. One common methodwhich is used, subject to navigation requirementsimmediately in front of the seawall, is to use concreteplaced by tremie to fill voids between the concreteblocks and rubble, after constructing a concretebagwork wall about one metre high doweled to therubble mound, one metre or so in front of the concreteblocks, to retain the concrete. The existing rubblemound in front of the concrete bagwork wall shouldbe supplemented as appropriate, and additional fillingplaced as necessary behind the seawall with the pavingrepaired to suit, after completion of the concreting.

14.4.3 Repairs to Concrete Blocks

In general, the only concrete blocks in seawall

1 4 . 4 . 2 修補堆石基床

若堆石基床給水流和波浪 擊以致損

壞，便可能令到護腳石和堤腳塊體底部淘

空，繼而使牆後的回填料流失。若海堤旁

的路面出現裂縫，通常便是這種損壞的最

初徵兆。裂縫是因為路面下的空隙造成

的，這種損壞一般只發生在波浪 擊較為

嚴重，而方塊海堤的堤腳高程又相對較

高，通常超過 - 2 . 0 m C D的地方。若一些

舊式海堤沒有採用標準的護腳石和堤腳

塊體設計規格，且建於外露岩石上，便特

別容易發生淘空現象。如懷疑底部給淘

空，應進行潛水檢查，以證實混凝土塊體

和堆石基床之間的接合處並無孔隙。若海

堤底部給淘空，一般會在堤前地方發現有

填料的痕跡。

一旦發現淘空現象，必須及時維修，

以免讓回填料進一步流失，使堤旁路面全

面下陷及海堤本身沉降、傾覆甚至塌毀。

維修方法取決於個別情況，一個常用的方

法，是先在海堤前方約一米處建造一個一

米高的袋裝混凝土護牆，榫接到堆石基床

上，然後用豎管澆灌混凝土於護牆圍 之

處，填滿混凝土塊體和堆石之間的孔隙。

使用這方法，須考慮海堤前方的通航需

要。混凝土澆注完成之後，應按需要補充

混凝土護牆前的堆石基床，及為海堤補充

回填料及修補路面。

1 4 . 4 . 3 修補混凝土塊體

一般來說，排水口的砌塊是方塊海堤

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construction which contain reinforcement are outfallblocks. For older seawalls, problems can be foundwith cracking and later concrete spalling due toreinforcement corrosion within the tidal and splashzones. Treatment should be carried out as described inSection 14.3.2, preferably as soon as cracks with ruststaining are detected.

14.4.4 Repairs to Granite Facing

Problems with granite facing relate to breakdownor loss of the mortar between the facing stones,apparently due to the chemical action of seawater orwave and current attack. Any sections where theoriginal pointing has been damaged or lost should berepointed immediately in order to prevent further lossof mortar and eventual loss of individual facing stones.In older walls, where individual facing stones havealready been lost, repairs can usually be carried outusing in situ concrete doweled to the existing backingconcrete, where appearance is not considered of majorimportance. Where it is considered essential that auniform granite facing finish should be maintained, it isnot normally possible to satisfactorily replace individualfacing stones without effectively reconstructing theadjacent section of granite facing, including the backingconcrete.

14.4.5 Repairs to Concrete Coping

Repairs to mass concrete copings relate mainly todamage from rope scrapes and vessels berthing, and tohorizontal displacement, usually soon afterconstruction of the coping and before finaldevelopment and paving of the land behind the seawallhas been carried out. Minor damage from rope scrapesand vessels need not normally be repaired unless thelength of seawall is particularly heavily used by thepublic and appearance is considered important. Moremajor damage can sometimes be effectively repairedusing epoxy mortar, but it is usually necessary to breakout and recast the full damaged length to produce asatisfactory result. Horizontal displacement of sectionsof coping should be treated on an individual basis,

結構中僅有的鋼筋混凝土塊體。舊海堤可

能出現的問題，是在潮位變動和浪濺區，

因鋼筋銹蝕而使混凝土裂開，然後剝落。

一旦發現帶有銹斑的裂紋，便須按第

1 4 . 3 . 2節的建議立即處理。

1 4 . 4 . 4 修補花崗岩面層

花崗岩面層的問題，主要是面層石之

間的灰漿損壞或流失。這顯然是由於海水

的化學作用，或波浪和水流 擊所致。為

防止灰漿進一步流失和個別面層塊石損

壞，在原來的勾縫灰漿損壞或流失時，便

應在該部分重新勾縫。有個別面層石流失

的舊海堤，如果外觀不太重要，可用現澆

混凝土修補，用榫栓連接到原有堤背混凝

土上。若花崗岩面層須保持均勻齊整，便

須連同花崗岩面層的相鄰部分，包括堤背

混凝土，一同修補，如果只是更換個別的

面層石，一般不會有令人滿意的效果。

1 4 . 4 . 5 修補混凝土牆帽

修補不含鋼筋的混凝土牆帽，主要是

針對由繩纜摩擦和船隻靠泊引起的損

壞，以及在牆帽完成後，在海堤旁土地尚

未發展和鋪面前的水平位移所引起的損

壞。除非一段海堤的使用率很高，兼且外

觀非常重要，否則繩纜和船舶造成的輕微

損壞不用修補。有些時侯，使用環氧樹脂

灰漿修補較嚴重的損壞，是非常有效的，

但要獲得令人滿意的效果，須清除全部損

壞的部分，然後重新澆注。牆帽的水平位

移，應視乎情況而個別處理。若剛竣工的

海堤向海位移時，通常不必立即修葺，可

安排於稍後時間，與相鄰區域的發展和鋪

面同時進行，那時可按需要清除損壞部

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depending on the circumstances. For newly completedseawalls, for displacement away from the sea, it is oftennot necessary to carry out immediate repairs, but toarrange for future repairs, including breaking out andrecasting as necessary, to be carried out at the time ofdevelopment and paving of the adjacent area.

14.5 Rubble Seawalls and Breakwaters

Damage to rubble seawalls and breakwaters willnormally only occur from wave attack during severestorms and typhoons. Minor damage to randomrubble armoured structures, involving displacement,slippage or general movement of armour stones, canusually be repaired by placing additional stones ofsimilar mass to infill any low regions and to build upthe overall profile back to the existing design profile.Minor damage to older smooth faced rubblearmoured structures, which normally consist of a singleclose fitting armour layer on rubble or quarry spalls,can most economically be repaired by infilling anyholes with carefully selected and fitted armour stones,after levelling up the underlayer.

Repairs to major damage to rubble structuresshould not be carried out until a full design check hasbeen carried out to determine whether the existingdesign, in particular the armour size, is in accordancewith recommended practice. When carrying outrepairs, the opportunity should be taken to modify orimprove the design as appropriate. When majordamage has occurred to older smooth faced rubblearmour structures, it may be quicker and moreeconomical to overlay the existing damaged slope withrandom rubble armour, subject to the existing slopenot being too smooth and regular, rather than tocompletely reconstruct the existing armour layer, whichwill often involve difficult excavation and sorting workand will result in the underlayers being further exposedduring the reconstruction period.

For comments on repairs to minor items, such assteps, bollards and light posts, see Sections 14.3.4 and14.3.5.

分，然後重新澆注。

1 4 . 5 堆石海堤和防波堤

堆石海堤和防波堤的損壞，通常是由

於受到強烈風暴和颱風引起的波浪襲擊

而造成。對於不規則堆石護面結構的輕微

損壞，包括位移、護面塊石滑動和一般錯

位等，修葺時可在缺損之處填入同質量的

塊石，重建至原設計剖面的規格。舊式光

滑護面堆石結構，一般只有單一的護面

層，由緊密結合的塊石組成，放於堆石或

礦場碎石上。這類堆石結構有輕微損壞

時，可以先整平墊層，然後將精選的合適

護面塊石填入孔隙中，這是最經濟的修葺

方法。

若堆石結構嚴重損壞，開始維修工程

前，應先進行全面核算，以確定原來的設

計，特別是護面規格方面，是否與現行的

設計規格相符。如有需要，維修時應同時

適當地修改設計的規格。舊式光滑護面堆

石結構嚴重損壞時，如果原有斜坡不太平

滑，較經濟和簡單的作法，是用不規則的

護面塊石覆蓋損壞的斜坡，這樣便不用全

面重建該護面，從而避免複雜的開挖和分

選石塊工作，和使墊層在重建期間進一步

外露。

有關小型項目，如階梯、繫船柱和燈

柱的修葺，可參考第 1 4 . 3 . 4節和第 1 4 . 3 . 5

節。

159

14.6 Ramps and Slipways

Repairs to ramps are rarely required. In exceptionalcircumstances, after a severe storm or typhoon,retrimming of the adjacent rubble foundation to avoidfouling by landing craft, or the placing of additionalrubble to avoid undermining the ramp slabs and toeblocks, may be required.

Major repairs to slipways, related to railmisalignment, material deterioration and desilting, areregularly required. Repair work is generally difficult,slow and expensive, being mostly underwater withpoor visibility. Close co-ordination with the slipwayuser is necessary as the slipway will need to betemporarily taken out of service while repair work isbeing carried out. Misalignment problems generallyrelate to differences in level, and occur for slipwayswith more than two parallel rails when the centre rail orrails settle more than the outer rails, causing the cradleto no longer run freely. The usual solution is to provideadditional packs, of steel or hardwood, for the rails orto replace the existing timber runners with thickersections.

During any realignment work, the opportunityshould be taken to replace any timber runners, steelrails, fixtures and fittings which have badlydeteriorated. Corrosion of the webs of the steel railswithin the tidal zone will usually be particularly severe.As a guide, steel rails should be replaced when anaverage effective reduction in web thickness of 10%over any length can be measured. For checkinghorizontal alignment during realignment workunderwater, a template based on the measured cradleroller dimensions, taking into account tolerances,should be used. When rail realignment work has beencompleted, any cradle deformation or defects,including sticking rollers, should be reported to theslipway user, for action by the appropriate maintenanceauthority.

For comments on desilting for slipways, see Section14.2. During the course of any slipway repair work,the opportunity should be taken to carry out anynecessary desilting work, even if such work has not

1 4 . 6 滑道和船排

滑道很少須要維修，只有在強烈風暴

或颱風吹襲之後，為避免被靠岸的船隻破

壞，才須要重新修整相鄰的堆石地基，或

為防止滑道平板和護腳塊體被淘空，而須

鋪放額外的堆石。

船排須要定期進行大修，主要針對不

準的鋼軌線向、變質材料和淤積物的疏

浚。修葺工作大多在水面下進行，能見度

差，因此難度甚大、時間長和費用高昂。

修葺期間，船排暫時不能使用；因此，應

和船排使用者密切配合。線向不準確問

題，一般與高低差有關，船排有兩條以上

並行鋼軌時，若中間的鋼軌沉降超過外鋼

軌，便會使承船架不能自由移動。常用的

解決方法，是在鋼軌加上額外的鋼製或硬

木墊件，或用較厚的木材更換原有軌枕。

鋼軌重新定線時，應同時更換嚴重損

壞的軌枕、鋼軌、附屬裝置和配件。在潮

位變動區的鋼軌腹板，往往銹蝕特別嚴

重。當測出鋼軌任何一段的腹板平均厚度

有效折減 1 0﹪以上時，便須將其更換。重

新定線時，須檢查水平線向，應採用模板

測度，模板應依據承船架滾軸尺度，加上

容許誤差而製成。鋼軌重新定線後，任何

承船架變形或缺陷，包括滾軸轉動有困

難，均應通知船排使用者，由有關維修部

門跟進。

有關船排清淤的要點，可參考第 1 4 . 2

節。船排修葺期間，即使船排使用者未有

明確要求，也應按需要疏浚淤積物，以減

少其封閉次數。

160

been requested specifically by the slipway user, toreduce to the minimum the number of times theslipway needs to be taken out of service.

14.7 Pumphouses

Repairs to pumphouses usually relate to particularoperational problems and are requested specifically bythe user, who should specify all technical requirements.The refixing and replacement of screen guides and thecleaning of the insides of screen guides and intakes arerelatively common items of work, and can usually becarried out by divers without undue difficulty. Forcomments on desilting in front of pumphouse intakes,see Section 14.2.

14.8 Navigation Aids

Maintenance and repair work to navigation aids,which generally consist of beacons and markers, ismainly limited to repainting and related treatment ofmiscellaneous steelwork items, such as light posts,ladders, mooring eyes and handrails. Reference may bemade to Section 14.3.5 for comments on the generalmaintenance and repair of such items.

14.9 Estimates for Future Maintenance

14.9.1 General

This Section gives comments and guidance on thepreparation of cost estimates for the futuremaintenance of various types of works, includingdredging, piers, seawalls and breakwaters. It should benoted that all projects are individual, and theinformation given below should be used as a generalguide only. When preparing estimates for a particularproject, all special circumstances should be taken intoaccount and, if possible, proposed maintenanceestimates should be cross-checked against actualmaintenance costs for similar works.

1 4 . 7 泵房

通常泵房的修葺與獨特的操作問題有

關，有需要時泵房使用者會提出具體要

求，和所有技術規格。重裝和更換攔污柵

導框，以及導板和進水口內部的清洗工作

是常見的維修項目，通常可由潛水員進

行，並不困難。有關泵房進水口前方的清

淤要點，可參考第 1 4 . 2節。

1 4 . 8 助航設備

助航設備包括燈塔和航標，保養與維

修工作，主要是為如燈柱、爬梯、繫船環

和欄桿等鋼結構，重新塗層和進行有關的

的處理。此類一般性保養與維修，可參考

第 1 4 . 3 . 5節。

1 4 . 9 預算保養費用

1 4 . 9 . 1 概述

本節為制定各類型工程的預算保養費

用提供指引，其中包括疏浚、碼頭、海堤

和防波堤。應當指出的是，任何工程項目

都具有其獨特性，下文所提供的資料，只

作一般性指引。為一具體工程項目制定預

算時，應考慮個別情況，如有可能，還須

利用同類型工程的實際保養費用來校

核。

161

14.9.2 Estimates for Dredging

Estimates of future maintenance costs are usuallydifficult to make with any confidence, being dependenton many factors often for which little or noinformation is available. Estimates may be required forfuture maintenance costs for capital dredging workscarried out as part of a project, or maintenancedredging costs for a project not necessarily involvingcapital dredging, e.g. the construction of a typhoonshelter. Factors which may influence estimates include :

(a) general siltation and its effects on the works,

(b) effects of currents and waves on the seabedwithin the area of the works and the possiblechanges in these caused by the construction ofthe works,

(c) deposits collecting at existing and planned futurestormwater drain, culvert and nullah outfalls,

(d) effects of construction of other works withinthe general area, and

(e) possible illegal dumping of construction andwaste materials.

Past records and studies indicate siltation rateswithin the general harbour area, including fairways butremote from outfalls, in the order of 50 to 100 mmper year. However, rates measured around some fairlyrecent works are in the order of 200 to 300 mm peryear, increasing markedly to 1000 mm per year ormore in particular locations, e.g. near outfalls.

14.9.3 Estimates for Maintenance of Piers

Records for existing structures indicate that annualrecurrent repair and maintenance costs for a public orferry pier is in the order of 0.5% of the capitalconstruction or replacement cost. This figure is basedon a typical reinforced concrete suspended deckstructure with a timber fendering system and

1 4 . 9 . 2 預算疏浚費用

保養費用由許多因素所決定，但往往

因為缺少或沒有可用的資料，而難以制定

準確的預算。在工程項目中，無論是否包

括基建性挖泥，都可能要為其制定維護性

疏浚費用的預算，後者可舉建造避風塘為

例。影響預算費用的因素包括﹕

( a ) 一般的淤積及其對工程的影響，

( b ) 水流和波浪對施工區內海床的影

響，以及其可能因工程引起的變

化，

(c) 原有和計劃中的雨水管、暗渠和明

渠排水口的沉積物，

( d ) 鄰近工程的影響，及

( e ) 非法棄置的建築材料和廢料。

以往的記錄和研究顯示，海港內（包

括遠離排水口的主航道）的淤積率，通常

約為每年 5 0至 1 0 0毫米。然而，近年在一

些工地附近測得的淤積率，卻達到每年

2 0 0至 3 0 0毫米。在一些特定區域，如排

水口附近，更高至每年1 0 0 0毫米或以上。

1 4 . 9 . 3 碼頭的預算保養費用

現有的記錄顯示，公用或渡輪碼頭的

每年維修與保養費用，約為基建或重建費

用的 0 . 5﹪。這是基於碼頭位於海港內或

其他有一定屏障掩護的地點，為典型鋼筋

混凝土承台式結構，具有木護舷系統，樁

柱是預應力混凝土樁或其他「無需維修」

162

prestressed concrete or other similar 'maintenance-free'piles, in the harbour or reasonably protected location.An allowance has been included for the regularmaintenance of miscellaneous minor items such ashandrails, light posts and notice boards.

14.9.4 Estimates for Maintenance of Seawalls

The annual recurrent repair and maintenance costsfor a length of vertical seawall has been estimated to bein the order of 0.1 to 0.3% of the capital constructionor replacement cost. These figures are based on typicalconcrete blockwork structures, with rubble moundfoundations and granite facing above about mid-tidelevel. The lower end of the range is applicable for wallswith foundations below about -20 mCD dredgedlevel, toe block levels lower than about -4 mCD andno or relatively few landing steps, bollards, noticeboards and miscellaneous fixtures and fittings. Theupper end of the range is applicable for walls withfoundations higher than about -10 mCD dredgedlevel, toe block levels higher than about -2 mCD, anda relatively large number of landing steps, bollards andmiscellaneous items.

For sloping rubble seawalls, annual repair andmaintenance costs are in the order of 0.2 to 0.3% of thecapital construction or replacement cost for relativelyprotected locations, and 0.4 to 0.6% for relativelyexposed locations. The lower ends of the ranges areapplicable for seawalls with foundations above about-10 mCD dredged level.

14.9.5 Estimates for Maintenance of Breakwaters

Annual recurrent repair and maintenance costs fortypical random placed rubble armoured breakwatersare in the order of 0.4 to 0.7% of the capitalconstruction or replacement cost for relativelyprotected locations, and 0.8 to 1.1% for relativelyexposed locations. As for sloping rubble seawalls inSection 14.9.4 above, the lower ends of the ranges areapplicable for structures with relatively deep

類型。這預算保養費用，已包括欄桿、燈

柱和告示牌等雜項的定期保養。

1 4 . 9 . 4 海堤的預算保養費用

直立式海堤的每年維修和保養費用，

約為基建或重建費用的 0 . 1至 0 . 3﹪。這預

算假設海堤為典型混凝土方塊體結構，具

有堆石基床及在中潮位以上築有花崗岩

面層。預算下限會適用於地基開挖到 - 2 0

m C D以下，堤腳高程在 - 4 m C D以下，

並只有較少甚至沒有登岸梯階、繫船柱、

告示牌和其他裝置與配件的牆體。預算上

限則適用於地基開挖高程在約 - 1 0 m C D

以上，堤腳高程約高於 - 2 m C D，並有較

多的登岸梯階、繫船柱和其他雜項的牆

體。

位於相對地掩蔽的水域的斜坡式堆石

海堤，每年維修與保養費用約是基建或重

建費用的 0 . 2至 0 . 3﹪；若在相對地開敞的

水域，則費用約為 0 . 4至 0 . 6﹪。這些預算

的下限，適用於地基開挖高程在約 - 1 0

m C D以上的海堤。

1 4 . 9 . 5 防波堤的預算保養費用

位於相對地掩蔽的水域的典型不規則

堆石防波堤，每年維修和保養費用約是基

建或重建費用的 0 . 4至 0 . 7﹪；若在相對地

開敞的水域，則費用約為 0 . 8至 1 . 1﹪。和

以上第 1 4 . 9 . 4節所述的斜坡式堆石海堤

一樣，這些預算的下限適合於地基較深的

結構，而上限則適合於地基較淺的結構。

163

foundations and the upper ranges for structures withrelatively shallow foundations.

164

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Goda, Y. (1971). Expected Rate of Irregular Wave Overtopping of Sea Walls. CoastalEngineering in Japan, vol. 14, pp 43-51.

Goda, Y. (1974). New Wave Pressure Formulae for Composite Breakwaters. Proceedings of theFourteenth Coastal Engineering Conference, Copenhagen, vol. III, pp 1702-1720.

Grove, G.C. & Little, D.H. (1951). The Design and Construction of Some Slipways up to 1,200 tons.The Institution of Civil Engineers Maritime Paper No. 17, 35 p.

Hong Kong Government (1992a). General Specification for Civil Engineering Works. HongKong Government, 3 volumes.

Hong Kong Government (1992b). Standard Method of Measurement for Civil EngineeringWorks. Hong Kong Government, 207 p.

Hogben, N., Dacunha, N. & Olliver, G. (1986). Global Wave Statistics. British MaritimeTechnology, 661 p.

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Hydraulics Research Station (1971b). H.K. Container Terminal - Study of Uplift Pressures andRetaining Rock Stability in a Model Representation of the Junction with Berth No. 1(Ex 559). Hydraulics Research Station, Wallingford, 14 p.

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Quinn, A.D. (1972). Design and Construction of Ports and Marine Structures. McGraw-HillInc., 611 p.

RO (1990). Surface Observations in Hong Kong 1990. Royal Observatory, Hong Kong.

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Tomlinson, M.J. (1987). Pile Design and Construction Practice. Viewpoint Publications, 378 p

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170

Table附表

171

172

LIST OF TABLES附表目錄

Table No Page No.附表編號 頁數

1 Basic Characteristics of Vessels -Local Craft Registry (September 1996)

船舶基本數據 -本地船隻登記處 (1996年9月)

173

2 Basic Characteristics of Vessels -H.K.F. Ferry Fleet (September 1996)

船舶基本數據 -香港小輪船隊 (1996年9月)

174

3 Basic Characteristics of Vessels -The Star Ferry Fleet (September 1996)

船舶基本數據 -天星小輪船隊 (1996年9月)

175

4 Basic Characteristics of Vessels -Discovery Bay Ferry Fleet (September 1996)

船舶基本數據 -愉景灣船隊 (1996年9月)

176

5 Five-day Normals of the Meteorological Elements forHong Kong1961 - 1990

香港氣象要素五天平均值

1961 - 1990177

6 Mean Hourly Wind Speeds - The Observatory1885 - 1939, 1947 - 1994

一小時平均風速 - 天文台

1885 - 1939, 1947 - 1994179

7 Mean Hourly Wind Speeds - Kai Tak Airport (South-east)1968 - 1994

一小時平均風速 - 啟德機場 (東南) 1968 -

1994179

8 Mean Hourly Wind Speeds - Waglan Island1975 - 1994

一小時平均風速 - 橫瀾島

1975 - 1994180

9 Mean Hourly Wind Speeds - Cheung Chau1970 - 1991

一小時平均風速 - 長洲

1970 - 1991180

10 Mean Wind Speeds - Waglan Island (North-east)1975 - 1994

平均風速 - 橫瀾島 (東北)

1975 - 1994181

11 Mean Wind Speeds - Waglan Island (East)1975 - 1994

平均風速 - 橫瀾島 (東)

1975 - 1994181

12 Mean Wind Speeds - Waglan Island (South-east)1975 - 1994

平均風速 - 橫瀾島 (東南)1975 - 1994年

181

13 Mean Wind Speeds - Waglan Island (South)1975 - 1994

平均風速 - 橫瀾島 (南)

1975 - 1994182

14 Mean Wind Speeds - Waglan Island (South-west)1975 - 1994

平均風速 - 橫瀾島 (西南)

1975 - 1994182

15 Mean Wind Speeds - Cheung Chau (South-east)1970 - 1991

平均風速 - 長洲 (東南)

1970 - 1991182

16 Mean Wind Speeds - Cheung Chau (South)1970 - 1991

平均風速 - 長洲 (南)

1970 - 1991183

17 Mean Wind Speeds - Cheung Chau (South-west)1970 - 1991

平均風速 - 長洲 (西南)

1970 - 1991183

173

Table No Page No.附表編號 頁數

18 Extreme Sea Levels - Quarry Bay/North Point1954 - 1994

極端海水位 - 魚涌/北角

1954 - 1994183

19 Extreme Sea Levels - Tai Po Kau1962 - 1994

極端海水位 - 大埔滘

1962 - 1994184

20 Extreme Sea Levels - Ko Lau Wan1974 - 1994

極端海水位 - 高流灣

1974 - 1994184

21 Extreme Sea Levels - Tsim Bei Tsui1974 - 1994

極端海水位 - 尖鼻咀

1974 - 1994184

22 Extreme Sea Levels - Waglan Island1976 - 1994

極端海水位 - 橫瀾島

1976 - 1994185

173

表 Table 1 Basic Characteristics of Vessels - Local Craft Register (September 1996)船舶基本數據 - 本地船隻登記處 (1996年9月)

No. of Vessels Licenced持有許可證的船隻

Approximate Dimensions (m)大約尺寸

Type/ Category of Vessel船舶種類

Mech.機動

Non-Mech.非機動

Total合計

Length O.A.全長

Beam船寬

Depth船深

Draft吃水

(m)

Displacement排水量

(t)

CarryingCapacity承載能力

ServiceSpeed航速(m/s)

1. Motor Launches & Ferry Vessels機動小輪、渡輪

1077 - 1077 6.5 - 62.0 2.4 - 19.1 1.0 - 4.0 0.5 - 3.0 15 - 3000 7 - 1400 pass. 3 - 17

2. Class I Passenger Sampans第I等 客運舢舨

126 118 244 5.0 - 7.8 2.1 - 3.5 0.7 - 1.0 0.3 - 0.7 4 - 25 1 - 5 pass. -

3. Class II Wooden, Steel Cargo / Work Barges第II等 木殼、鋼殼貨運躉船

437 1838 2275 6.2 - 133.6 1.8 - 29.9 2.0 - 4.0 1.0 - 3.0 25 - 3200 25 - 2200 t 2 - 4

4. Class III Stationary Craft第III等 固定船隻

- 241 241 4.6 - 45.5 2.5 - 24.6 1.0 - 4.0 0.7 - 3.0 13 - 6200 - -

5. Class IV Fishing, Misc. Craft第IV等 漁船、雜貨船隻

2005 2853 4858 3.7 - 132.3 1.0 - 30 0.7 - 4.0 0.3 - 3.0 20 - 3200 15 - 2200 t 2 - 5

6. Class V Trading Vessels第V等 營業船

72 - 72 7.7 - 36.1 3.1 - 8.5 1.0 - 3.0 0.7 - 2.5 20 - 40 5 - 6 t 5 - 7

7. Class VI Fishing Vessels第VI等 漁船

3606 2 3608 6.7 - 39.3 2.8 - 19.3 1.0 - 2.0 0.7 - 1.5 16 - 350 - 3 - 15

8. Class VII Floating Dock / Workshops第VII等 浮塢、浮置工場

- 13 13 23.2 - 270.0 8.5 - 59.2 2.0 - 3.0 1.0 - 2.5 150 - 58000 - -

9. Class VIII Float Restaurant第VIII等 水上食肆

- 3 3 52.5 - 76.2 15.1 - 22.7 - - - - -

10. Various Classes Pleasure Vessels各等級遊艇

5860 - 5860 1.7 - 62.5 1.7 - 11.3 0.3 - 5.0 0.2 - 4.5 0.5 - 800 1 - 200 pass. 2 - 30

Total 總 計 13183 5068 18251

Mech. = Mechanical (機動)Non-Mech. = Non-mechanical (非機動)Pass. = Passenger (乘客)

174

表 Table 2 Basic Characteristics of Vessels - H.K.F. Ferry Fleet (September 1996)船舶基本數據 - 香港小輪船隊 (1996年9月)

Type of Vessel船型種類

LengthO.A.全長

(m)

Beam船寬

(m)

Draft吃水

(m)

Displacement排水量

(t)

Carrying Capacity承載能力

Pass. Veh.乘客 汽車

ServiceSpeed航速

(m/s)

VEHICULAR FERRIES 載客/汽車混合渡輪

1. Double End Double Deck(Displacement < 1000t)雙向雙層載客/汽車混合渡輪(排水量<1000t)

52.0 12.8 2.9 - 3.0 907 - 953 436-897 30-55 5.3-5.4

2. Double End Double Deck(Displacement > 1000t)雙向雙層載客/汽車混合渡輪(排水量>1000t)

64.0 13.4 3.2 1166 - 1366 440 65-70 5.2-5.4

3. Double End Triple Deck(Night Club/Restaurant)雙向三層載客/汽車混合渡輪(備有夜總會/餐廳)

64.0 13.4 3.3 - 3.4 1326 - 1379 482-492 60 5.4

PASSENGER FERRIES 載 客 渡 輪

4. Single End Double Deck(Displacement < 200t)單向雙層載客渡輪(排水量<200t)

30.0 7.0 1.5 107 436 6.1

5. Single End Double Deck(Displacement 200 - 300t)單向雙層載客渡輪(排水量200-300t)

31.6 - 44.2 7.3 - 8.2 1.9 - 2.8 234 - 299 469 - 676 4.8 - 7.4

6. Single End Double Deck(Displacement > 300t)單向雙層載客渡輪(排水量>300t)

43.1 8.2 2.4 301 - 309 596 - 598 6.9

7. Single End Triple Deck單向三層載客渡輪

49.4 - 65.5 10.1 - 11.6 2.2 - 2.8 534 - 965 1071- 1646 6.7 - 8.2

8. Double End Double Deck雙向雙層載客渡輪

35.7 - 64.0 8.4 - 13.4 2.2 - 3.2 357 - 1366 717 - 1697 5.1 - 6.1

9. Double End Double Deck(Night Club/Restaurant)雙向雙層載客渡輪(備有夜總會/餐廳)

64.0 13.4 3.2 1113 536 5.9

10. Hovercraft HM2飛翔船

15.7 - 18.2 5.8 1.6 - 1.7 21 - 28 77 - 108 13.4

11. Hoverferry HM5飛翔船

26.2 9.7 2.6 144 200 14.4

12. Waterjet Catamaran噴射推動雙體船

40.0 10.1 1.7 136 433 17.0

Pass. = Passenger (乘客)Veh. = Vehicle (汽車)

175

表 Table 3 Basic Characteristics of Vessels - The Star Ferry Fleet (September 1996)船舶基本數據 - 天星小輪船隊 (1996年9月)

Name of Vessel船名

Length O.A.全長

(m)

Beam船寬

(m)

Draft吃水

(m)

Displacement排水量

(t)

PassengerCarryingCapacity載客量

ServiceSpeed航速(m/s)

1. Celestial Star天星

2. Meridian Star午星

3. Solar Star日星

4. Northern Star北星

5. Night Star夜星

6. Shinning Star輝星

33.8 8.6 2.4 241 566 5.7

7. Day Star晨星

8. Twinkling Star熒星

9. Morning Star曉星

10. Silver Star銀星

11. Pacific Princess (launch)太平洋公主

39.2 7.9 3.8 251 100 6.2

12. Golden Star金星 44.4 9.3 3.6 383 762 6.0

13. World Star世星

176

表 Table 4 Basic Characteristics of Vessels - Discovery Bay Ferry Fleet (September 1996)船舶基本數據 - 愉景灣船隊 (1996年9月)

Type & Name of Vessel船型種類及船名

Length O.A.船長

(m)

Beam船寬

(m)

Draft吃水

(m)

Displacement排水量

(t)

PassengerCarryingCapacity載客量

ServiceSpeed航速(m/s)

1. HM218 Sidewall HC (RTS201)飛翔船

2. HM218 Sidewall HC (RTS202)飛翔船

18.3 6.1 1.7 28.4 100 14.4

3. HM218 Sidewall HC (RTS203)飛翔船

4. Monohull GRP PB (DB8)單層船

5. Monohull GRP PB (DB9)單層船

19.7 5.4 1.7 43 130 9.8

6. Monohull GRP PB (DB23)單層船

7. Waterjet Monohull PB (DB12)單體噴射船

8. Waterjet Monohull PB (DB15)單體噴射船

9. Waterjet Monohull PB (DB16)單體噴射船

10. Waterjet Monohull PB (DB19)單體噴射船

35.5 7.7 1.2 93 300 12.8

11. Waterjet Monohull PB (DB20)單體噴射船

12. Waterjet Monohull PB (DB21)單體噴射船

13. Waterjet Monohull PB (DB22)單體噴射船

14. Catamaran PB (DB1)雙體船

15. Catamaran PB (DB2)雙體船

42.0 11.5 1.3 168 500 17.0

16. Catamaran PB (DB3)雙體船

177

表 Table 5 Five-day Normals of the Meteorological Elements for Hong Kong香港氣象要素五天平均值1961 - 1990

Air Temperature氣 溫

Wind風

M.S.L. Pressure平均海平面氣壓

(hPa)

Mean DailyMaximum日最高平均

(° C)

Mean平均

(° C)

Mean DailyMinimum日最低平均

(° C)

Wet-BulbTemperature

濕球溫度

(° C)

Dew Point露點

(° C)

RelativeHumidity相對濕度

(% )

Rainfall(Mean Daily)

降雨量(日平均)(mm)

Amountof Cloud雲量

(% )

Sunshine(Mean Daily)

日照(日平均)(hr)

PrevailingDirection盛行風向

(deg.)

Mean Speed平均風速

(m/s)

Jan 1 - 5 1020.5 18.5 15.7 13.5 12.6 9.3 68 1.0 56 5.1 010 7.21月 6 - 10 1020.6 18.9 16.1 13.9 13.0 9.8 68 0.4 51 5.7 070 6.2

11 - 15 1020.5 18.5 15.6 13.3 12.6 9.5 69 0.5 52 5.3 070 6.6 16 - 20 1020.3 18.5 15.6 13.3 12.8 10.1 72 0.7 55 5.4 070 6.7 21 - 25 1019.8 19.1 16.2 14.0 13.6 11.2 74 0.6 62 4.6 070 6.4 26 - 30 1019.3 18.7 16.0 13.9 13.6 11.3 76 0.9 69 3.8 070 6.6 31 - 4 1019.9 17.3 14.8 12.8 12.4 10.1 75 1.0 71 3.5 070 6.9

Feb 5 - 9 1019.6 17.8 15.3 13.3 13.1 11.0 77 1.7 72 3.6 070 6.82月 10 - 14 1019.1 18.8 16.0 13.9 13.9 12.0 78 1.3 69 3.9 070 6.1

15 - 19 1018.0 19.6 16.8 14.7 14.6 12.7 78 1.3 70 4.0 070 6.1 20 - 24 1017.5 19.2 16.7 14.7 14.7 13.1 81 2.2 80 2.6 070 6.4 25 - 1 1018.5 18.3 15.8 13.8 13.7 11.7 78 2.8 78 2.9 010 7.1

Mar 2 - 6 1018.1 19.7 16.9 14.8 14.8 12.8 79 2.4 75 3.3 070 6.33月 7 - 11 1017.5 20.6 17.9 16.1 15.9 14.3 80 0.9 76 3.2 070 6.2

12 - 16 1016.2 21.8 18.8 16.6 16.8 15.3 81 1.7 71 3.7 070 5.5 17 - 21 1014.8 22.1 19.2 17.2 17.3 16.0 82 2.4 76 3.1 080 6.0 22 - 26 1015.5 21.4 18.8 16.8 16.9 15.5 82 3.4 81 2.5 070 6.8 27 - 31 1014.9 22.7 20.0 18.0 18.0 16.7 82 2.1 78 3.0 080 5.5

Apr 1 - 5 1014.5 22.8 20.2 18.2 18.3 17.0 83 6.3 84 2.5 080 6.24月 6 - 10 1013.8 24.0 21.3 19.3 19.4 18.2 83 6.3 81 2.9 080 5.6

11 - 15 1013.7 24.2 21.6 19.6 19.5 18.3 83 4.6 79 3.1 080 5.6 16 - 20 1012.6 25.4 22.6 20.6 20.6 19.5 83 3.4 79 3.9 080 5.2 21 - 25 1012.0 26.6 23.6 21.5 21.5 20.3 83 4.8 71 5.1 080 4.9 26 - 30 1011.9 26.6 23.8 21.9 21.7 20.7 83 6.9 76 4.4 080 4.9

May 1 - 5 1010.7 27.6 24.7 22.7 22.6 21.6 84 8.0 75 4.7 080 4.85月 6 - 10 1010.6 28.6 25.7 23.6 23.4 22.3 82 6.6 72 5.4 090 4.5

11 - 15 1009.7 28.6 25.9 23.9 23.8 22.8 84 12.1 76 4.7 090 5.1 16 - 20 1008.8 28.8 26.0 24.0 23.6 22.4 81 12.3 70 5.4 080 6.3 21 - 25 1008.2 28.8 26.2 24.3 23.9 22.9 83 7.6 73 4.8 090 5.4 26 - 30 1007.1 29.4 26.8 24.8 24.5 23.5 83 14.3 75 4.6 090 5.5 31 - 4 1006.8 29.5 26.9 25.0 24.8 23.8 84 15.2 78 4.2 090 5.9

Jun 5 - 9 1006.9 29.2 26.8 25.0 24.6 23.7 84 12.9 77 4.5 090 5.96月 10 - 14 1006.4 30.0 27.5 25.6 25.1 24.2 83 12.8 75 5.3 090 5.7

15 - 19 1005.6 30.6 28.1 26.2 25.6 24.6 82 16.0 74 5.6 220 6.3 20 - 24 1005.7 31.2 28.5 26.6 26.0 25.0 82 7.7 71 6.6 100 5.8 25 - 29 1005.3 31.2 28.5 26.6 26.0 25.0 82 11.2 73 5.9 190 6.1 30 - 4 1005.2 31.3 28.7 26.7 26.1 25.1 81 11.3 69 6.8 230 5.5

Observed at觀測地點

The Observatory天文台

King’s Park京士柏

Waglan Island橫瀾島

178

表 Table 5 Five-day Normals of the Meteorological Elements for Hong Kong (Continued)香港氣象要素五天平均值 (續)1961 - 1990

Air Temperature氣 溫

Wind風

M.S.L. Pressure平均海平面氣壓

(hPa)

Mean DailyMaximum日最高平均

(° C)

Mean平均

(° C)

Mean DailyMinimum日最低平均

(° C)

Wet-BulbTemperature

濕球溫度

(° C)

Dew Point露點

(° C)

RelativeHumidity相對濕度

(% )

Rainfall(Mean Daily)

降雨量(日平均)(mm)

Amount ofCloud雲量

(% )

Sunshine(Mean Daily)

日照(日平均)(hr)

PrevailingDirection盛行風向

(deg.)

Mean Speed平均風速

(m/s)

Jul 5 - 9 1005.7 31.8 29.1 27.0 26.2 25.1 80 5.8 62 8.0 230 5.47月 10 - 14 1005.8 31.7 28.9 26.7 26.1 25.0 80 10.8 65 7.7 230 5.5

15 - 19 1005.6 31.7 28.8 26.5 26.0 24.9 80 11.3 63 8.1 230 5.5 20 - 24 1005.7 31.5 28.7 26.5 26.1 25.0 81 9.7 67 7.4 230 5.5 25 - 29 1004.3 31.3 28.5 26.3 25.8 24.7 81 12.8 65 6.8 230 5.6 30 - 3 1004.4 31.2 28.5 26.3 26.0 25.0 82 14.9 67 6.6 230 5.4

Aug 4 - 8 1004.8 31.5 28.7 26.5 26.1 25.1 82 8.7 66 6.9 230 4.78月 9 - 13 1004.8 31.1 28.4 26.3 25.9 24.9 82 14.7 69 6.6 090 5.7

14 - 18 1004.8 31.4 28.4 26.2 25.9 24.8 82 14.7 66 6.8 090 5.1 19 - 23 1004.8 31.4 28.4 26.2 25.8 24.7 81 14.3 65 6.8 230 5.5 24 - 28 1006.1 31.4 28.5 26.4 25.8 24.6 80 9.3 64 6.8 090 4.7 29 - 2 1006.4 31.1 28.2 26.0 25.6 24.5 81 12.1 66 6.1 090 4.6

Sep 3 - 7 1006.9 31.0 28.2 25.9 25.5 24.4 81 12.6 65 6.5 090 5.79月 8 - 12 1007.6 30.9 27.9 25.7 24.9 23.6 78 12.9 60 6.6 090 5.0

13 - 17 1008.9 30.6 27.8 25.7 24.6 23.0 76 5.8 63 6.2 090 5.5 18 - 22 1009.9 30.2 27.5 25.3 24.3 22.8 77 6.9 63 6.0 090 6.4 23 - 27 1010.6 29.6 27.0 24.9 24.0 22.6 78 10.3 64 5.5 090 6.9 28 - 2 1011.3 29.1 26.6 24.6 23.6 22.1 77 7.9 63 5.5 090 7.6

Oct 3 - 7 1012.4 29.1 26.4 24.3 22.8 20.9 73 4.6 53 6.6 090 6.810月 8 - 12 1013.3 28.6 25.9 23.9 22.3 20.4 72 3.5 53 6.8 090 7.5

13 - 17 1013.4 28.4 25.6 23.5 22.1 20.2 73 7.9 55 6.5 090 8.1 18 - 22 1014.6 27.4 24.8 22.8 21.5 19.5 74 5.3 56 6.2 080 8.2 23 - 27 1015.3 26.9 24.3 22.3 20.9 18.9 73 3.0 60 5.7 080 7.8 28 - 1 1016.4 26.0 23.3 21.3 19.9 17.8 72 3.3 53 6.3 090 7.1

Nov 2 - 6 1016.7 26.1 23.3 21.2 19.8 17.7 72 0.9 50 6.7 080 7.111月 7 - 11 1016.5 25.0 22.5 20.5 19.2 17.1 72 1.8 61 5.4 080 8.1

12 - 16 1017.6 24.3 21.7 19.6 18.5 16.2 72 1.6 63 5.0 080 7.6 17 - 21 1018.2 23.9 21.1 18.8 17.5 14.8 69 1.2 51 6.4 080 7.3 22 - 26 1019.0 22.9 20.1 17.9 16.2 12.9 65 0.6 49 6.1 080 7.7 27 - 1 1020.1 21.9 18.8 16.2 14.8 11.2 63 0.8 44 6.7 360 7.5

Dec 2 - 6 1020.0 21.7 18.7 16.4 15.1 11.9 67 1.7 44 6.3 080 6.712月 7 - 11 1019.7 21.6 18.6 16.3 15.3 12.4 69 0.6 44 6.5 080 6.8

12 - 16 1020.7 20.3 17.5 15.2 13.9 10.6 66 0.2 44 6.3 080 7.4 17 - 21 1020.3 20.3 17.6 15.4 14.4 11.4 69 1.1 52 5.5 080 6.8 22 - 26 1019.8 20.0 17.2 14.9 14.1 11.1 70 0.6 53 5.4 070 6.9 27 - 31 1020.3 18.9 16.2 14.0 13.2 10.2 69 1.1 60 4.8 070 7.3

Observed at觀測地點

The Observatory天文台

King’s Park京士柏

Waglan Island橫瀾島

179

表 Table 6 Mean Hourly Wind Speeds - The Observatory一小時平均風速 - 天文台1885 - 1939, 1947 - 1994 (m/s)

Return Period (yr)重現期

N北

NE東北

E東

SE東南

S南

SW西南

W西

NW西北

5 16 21 24 21 15 16 13 13

10 19 25 27 25 18 19 16 16

20 22 29 31 29 21 22 18 18

50 26 34 36 34 24 25 21 22

100 29 38 39 38 27 28 23 24

200 31 42 43 42 30 30 26 27

表 Table 7 Mean Hourly Wind Speeds - Kai Tak Airport (South-east)一小時平均風速 - 啟德機場 (東南)1968 - 1994 (m/s)

Return Period (yr)重現期

N北

NE東北

E東

SE東南

S南

SW西南

W西

NW西北

5 15 16 21 19 16 17 16 13

10 17 18 24 22 18 20 18 15

20 19 20 27 25 21 24 20 16

50 22 22 31 29 24 28 23 18

100 24 24 34 32 27 31 25 19

200 26 26 37 35 29 34 28 21

180

表 Table 8 Mean Hourly Wind Speeds - Waglan Island一小時平均風速 - 橫瀾島1975 - 1994 (m/s)

Return Period (yr)重現期

N北

NE東北

E東

SE東南

S南

SW西南

W西

NW西北

5 21 23 28 24 22 22 19 14

10 24 27 32 29 26 27 22 16

20 26 31 36 35 30 32 26 18

50 30 35 41 41 36 37 31 21

100 32 38 45 45 39 41 34 23

200 35 41 48 50 43 45 37 25

表 Table 9 Mean Hourly Wind Speeds - Cheung Chau一小時平均風速 - 長洲1970 - 1991 (m/s)

Return Period (yr)重現期

N北

NE東北

E東

SE東南

S南

SW西南

W西

NW西北

5 17 19 24 25 21 19 17 17

10 19 22 28 30 27 23 21 20

20 21 25 31 35 32 28 25 23

50 23 29 36 41 38 34 30 27

100 25 32 39 45 43 38 34 30

200 27 35 42 49 48 42 37 34

181

表 Table 10 Mean Wind Speeds - Waglan Island (North-east)平均風速 - 橫瀾島 (東北)1975 - 1994 (m/s)

Return Period (yr)Duration (hr)歷時

重現期 1 2 3 4 6 105 23 22 22 20 19 1710 27 26 25 23 21 2020 31 29 28 26 24 2350 35 33 32 29 28 27

100 38 36 35 32 31 30200 41 39 38 35 34 33

表 Table 11 Mean Wind Speeds - Waglan Island (East)平均風速 - 橫瀾島 (東)1975 - 1994 (m/s)

Return Period (yr)Duration (hr)歷時

重現期 1 2 3 4 6 105 28 27 26 26 22 2110 32 32 31 30 24 2320 36 35 34 34 26 2550 41 40 39 38 30 28

100 45 44 43 42 32 30200 48 47 46 45 34 33

表 Table 12 Mean Wind Speeds - Waglan Island (South-east)平均風速 - 橫瀾島 (東南)1975 - 1994 (m/s)

Return Period (yr)Duration (hr)歷時

重現期 1 2 3 4 6 105 24 23 22 21 18 1310 29 28 26 25 23 1520 35 33 31 30 27 1850 41 39 37 36 32 21

100 45 43 42 40 36 23200 50 48 46 44 40 25

182

表 Table 13 Mean Wind Speeds - Waglan Island (South)平均風速 - 橫瀾島 (南)1975 - 1994 (m/s)

Return Period (yr)Duration (hr)歷時

重現期 1 2 3 4 6 10

5 22 21 17 16 14 1110 26 25 20 19 17 1420 30 29 23 22 20 1750 36 34 28 27 24 20

100 39 38 31 30 27 22200 43 42 34 33 30 25

表 Table 14 Mean Wind Speeds -Waglan Island (South-west)平均風速 - 橫瀾島 (西南)1975 - 1994 (m/s)

Return Period (yr)Duration (hr)歷時

重現期 1 2 3 4 6 10

5 22 18 17 15 14 1210 27 21 20 18 16 1320 32 24 23 20 19 1550 37 28 26 23 21 18

100 41 31 29 25 23 19200 45 34 32 27 26 21

表 Table 15 Mean Wind Speeds - Cheung Chau (South-east)平均風速 - 長洲 (東南)1970 - 1991 (m/s)

Return Period (yr)Duration (hr)歷時

重現期 1 2 3 4 6 10

5 25 23 18 17 15 1210 30 28 20 20 18 1420 35 33 23 22 20 1650 41 39 26 26 23 18

100 45 43 29 28 25 20200 49 48 32 31 27 22

183

表 Table 16 Mean Wind Speeds - Cheung Chau (South)平均風速 - 長洲 (南)1970 - 1991 (m/s)

Return Period (yr)Duration (hr)歷時

重現期 1 2 3 4 6 10

5 21 20 18 17 14 9

10 27 26 22 21 19 11

20 32 31 27 26 23 13

50 38 38 33 32 29 17

100 43 43 38 36 33 19

200 48 47 42 40 37 21

表 Table 17 Mean Wind Speeds - Cheung Chau (South-west)平均風速 - 長洲 (西南)1970 - 1991 (m/s)

Return Period (yr)Duration (hr)歷時

重現期 1 2 3 4 6 105 19 15 14 12 11 910 23 19 18 15 14 1020 28 23 21 18 16 1150 34 28 25 22 19 13

100 38 32 29 25 22 14200 42 35 32 28 24 16

表 Table 18 Extreme Sea Levels - Quarry Bay/North Point極端海水位 - 魚涌/北角1954 - 1994

Return Period (yr)重現期

Sea Level (mCD)海水位

2 2.85 3.1

10 3.220 3.350 3.5100 3.6200 3.8

184

表 Table 19 Extreme Sea Levels - Tai Po Kau極端海水位 - 大埔滘1962 - 1994

Return Period (yr)重現期

Sea Level (mCD)海水位

2 3.15 3.5

10 3.820 4.050 4.3100 4.6200 4.8

表 Table 20 Extreme Sea Levels - Ko Lau Wan極端海水位 - 高流灣1974 - 1994

Return Period (yr)重現期

Sea Level (mCD)海水位

2 2.85 3.0

10 3.120 3.250 3.4100 3.5200 3.6

表 Table 21 Extreme Sea Levels - Tsim Bei Tsui極端海水位 - 尖鼻咀1974 - 1994

Return Period (yr)重現期

Sea Level (mCD)海水位

2 3.25 3.5

10 3.620 3.850 4.0100 4.2200 4.3

185

表 Table 22 Extreme Sea Levels - Waglan Island極端海水位 - 橫瀾島1976 - 1994

Return Period (yr)重現期

Sea Level (mCD)海水位

2 2.65 2.9

10 3.020 3.250 3.4100 3.6200 3.7

186

187

Figure附圖

188

189

LIST OF FIGURES附圖目錄

Figure No. Page No.附圖編號 頁數

1 Wind Record Stations 風觀測站 191

2 Annual Wind Rose 年風玫瑰圖 192

3 Deep-water Wave Prediction Curves 深水波浪預測曲線 193

4 Shallow-water Wave Prediction Curves -

Constant Depth 6.0 metres

淺水波浪預測曲線 -

定常水深6.0米194

5 Shallow-water Wave Prediction Curves -

Constant Depth 9.0 metres

淺水波浪預測曲線 -

定常水深9.0米194

6 Shallow-water Wave Prediction Curves -

Constant Depth 12.0 metres

淺水波浪預測曲線 -

定常水深12.0米195

7 Shallow-water Wave Prediction Curves -

Constant Depth 15.0 metres

淺水波浪預測曲線 -

定常水深15.0米195

8 Tide Gauge Locations 潮位計位置圖 196

9 Morison's Equation, Linear (Airy) Wave Theory Variation

of Inertia Wave Force with Depth

Morison公式，線性波浪理論 (Airy) 波浪

慣性力隨深度的變化

197

10 Morison's Equation, Linear (Airy) Wave Theory Variation

of Drag Wave Force with Depth

Morison公式，線性波浪理論 (Airy) 波浪

拖曳力隨深度的變化

198

11 Morison's Equation, Linear (Airy) Wave Theory Variation

of Percentage of Total Inertia Wave Force with Depth

Water Level at 0.4d above Still-water Level

Morison公式，線性波浪理論 (Airy)總波浪

慣性力百分數隨深度的變化

水位在靜水面以上0.4d

199

12 Morison's Equation, Linear (Airy) Wave Theory Variation

of Percentage of Total Inertia Wave Force with Depth

Water Level at 0.3d above Still-water Level

Morison公式，線性波浪理論 (Airy) 總波

浪慣性力百分數隨深度的變化

水位在靜水面以上0.3d

200

13 Morison's Equation, Linear (Airy) Wave Theory Variation

of Percentage of Total Inertia Wave Force with Depth

Water Level at 0.2d above Still-water Level

Morison公式，線性波浪理論 (Airy) 總波

浪慣性力百分數隨深度的變化

水位在靜水面以上0.2d

201

14 Morison's Equation, Linear (Airy) Wave Theory Variation

of Percentage of Total Inertia Wave Force with Depth

Water Level at 0.1d above Still-water Level

Morison公式，線性波浪理論 (Airy) 總波

浪慣性力百分數隨深度的變化

水位在靜水面以上0.1d

202

15 Morison's Equation, Linear (Airy) Wave Theory Variation

of Percentage of Total Inertia Wave Force with Depth

Water Level at Still-water Level

Morison公式，線性波浪理論 (Airy) 總波

浪慣性力百分數隨深度的變化

水位在靜水面

203

190

Figure No. Page No.附圖編號 頁數

16 Morison's Equation, Linear (Airy) Wave Theory Variation

of Percentage of Total Drag Wave Force with Depth

Water Level at 0.4d above Still-water Level

Morison公式，線性波浪理論 (Airy) 總波

浪拖曳力百分數隨深度的變化

水位在靜水面以上0.4d

204

17 Morison's Equation, Linear (Airy) Wave Theory Variation

of Percentage of Total Drag Wave Force with Depth

Water Level at 0.3d above Still-water Level

Morison公式，線性波浪理論 (Airy) 總波

浪拖曳力百分數隨深度的變化

水位在靜水面以上0.3d

205

18 Morison's Equation, Linear (Airy) Wave Theory Variation

of Percentage of Total Drag Wave Force with Depth

Water Level at 0.2d above Still-water Level

Morison公式，線性波浪理論 (Airy) 總波

浪拖曳力百分數隨深度的變化

水位在靜水面以上0.2d

206

19 Morison's Equation, Linear (Airy) Wave Theory Variation

of Percentage of Total Drag Wave Force with Depth

Water Level at 0.1d above Still-water Level

Morison公式，線性波浪理論 (Airy) 總波

浪拖曳力百分數隨深度的變化

水位在靜水面以上0.1d

207

20 Morison's Equation, Linear (Airy) Wave Theory Variation

of Percentage of Total Drag Wave Force with Depth

Water Level at Still-water Level

Morison公式，線性波浪理論 (Airy) 總波

浪拖曳力百分數隨深度的變化

水位在靜水面

208

21 Rock Armour Design Curves - Structure Trunk 護面塊石設計曲線 - 堤身 209

22 Rock Armour Design Curves - Structure Head 護面塊石設計曲線 - 堤頭 210