1 Earthquake Preparedness and Countermeasures in Osaka Municipal Waterworks Bureau Osaka Municipal Waterworks Bureau Kazuya YAMANO

1

Earthquake Preparedness and Countermeasures in

Osaka Municipal Waterworks Bureau

Osaka Municipal Waterworks BureauKazuya YAMANO

OSAKA Municipal Waterworks Bureau 2

大阪市水道局

Osaka Municipal Waterworks

Japan

OSAKA City

Kobe City

Purification plants: 3 plantsDistribution pipes: 5,000 kmWater supply capacity: 2,430,000 m3/day

Area ： 211km2

Population ： 2.6 million


大阪市水道局

Improving earthquake preparednessImproving earthquake preparedness

Review of scenario earthquakes (2004 ～ )

Outline of Earthquake Preparedness Efforts

Earthquake Preparedness Improvement Plan 21(1996)

Damage of distribution pipes

Kobe Earthquake (1995)

Investigation of seismic motion

Tsunami

Influence on purification plants

Estimation Estimation


大阪市水道局








Tsunami




大阪市水道局

8 Basic Elements

Osaka Municipal Waterworks Earthquake Preparedness Improvement Plan 21

(1)Improving Earthquake Resistance of Key Facilities(2)Establishing a Water Supply and Distribution Center

Network(3)Improving Compatibility among Different Distribution

Systems(4)Countermeasures against Power Failure(5)Expanding Emergency Material Stock System (6)Establishing Stable Water Supply Routes to Man-

made Islands(7)Improving Reliability of Information and

Communication System(8)Improving Earthquake Resistance of Headquarters

Necessary for Disaster Relief and Recovery Activities


大阪市水道局Earthquake Preparedness (1)

Ductile Iron PipeDuctile Iron Pipe

Length of cast iron pipes

1,278 km (1997)

870 km (2005)

Improving earthquake resistance of distribution pipe network


大阪市水道局

Sakishima Distribution Plant

NAGAI

SAKISHIMA

Osaka City

KUNIJIMA

JOTO

OTEMAE

TATSUMI

SUMIYOSHI

SUMINOE

OYODO

MINATO

Nagai : 42,000 ㎥Sakishima : 30,000 ㎥Total : 72,000 ㎥ UP

Capacity of distribution reservoir

Nagai Distribution Plant

Distribution Plant (existing)

Distribution Plant (newly-built)

Earthquake Preparedness (2)

Increasing capacity of drinking water reservoirs


大阪市水道局

Polyethylene Bag (3L, 10L)Water Supply Truck

Temporary Water Tank（ 4m3） Pipe Stock

Earthquake Preparedness (3)

Sufficiency of emergency materials


大阪市水道局Earthquake Preparedness (4)

Realization of effective emergency activity

Headquarters

Disaster Site

Disaster InformationManagement System

InstructionsReport


大阪市水道局








Tsunami




大阪市水道局Scenario Earthquakes

(a)

(b)(c)

(d)

(e)

(a) Uemachi fault(b) Ikoma fault(c) Arima-Takatsuki-kozosen f

ault(d) Chuo-kozosen fault (e) Nankai trough (Tonankai-

Nankai Earthquake)

Tsunami


大阪市水道局








Tsunami




大阪市水道局

Japan

OsakaKobe

TonankaiNank

ai

Tonankai & Nankai Earthquake (1)

Committee on Tonankai & Nankai Tsunami

- Tonankai Earthquake : about 60%- Nankai Earthquake : about 50%

Scenario Earthquake

Earthquake Occurrence Probability (within next 30 years)


大阪市水道局Tonankai & Nankai Earthquake (2)

Scenario Earthquake

- Simultaneous Occurrence of Tonankai & Nankai Earthquakes

- JMA Magnitude : 8.4

Earthquake Occurrence Probability


Japan

OsakaKobe

TonankaiNank

ai


大阪市水道局Tonankai & Nankai Earthquake (3)

Chairperson: Prof. Kawata ( Kyoto Univ. )

Making map of inundation by Tsunami Possibility of tsunami going over Yodo River Large Weir revealed

Members: Osaka City, Osaka Pref., Wakayama Pref.

Scenario Earthquake

Earthquake Occurrence Probability


Osaka City

Inundation map


大阪市水道局Preparedness against tsunami caused by Tonankai & Nankai Earthquake

Kunijima P.P1,180,000m3／ day

Yodo River

Lower Flow(Osaka Bay)

Upper Flow

Examination of Intake of Kunijima purification plant along Yodo River ：

(1) Chloride ion (2) Turbidity

Overflow

Committee on the Influence on Water Treatment by Tsunami in Yodo River

Yodo River Large WeirIntake of

Kunijima P.P


大阪市水道局 Tsunami simulation Tsunami simulation

Tsunami arrives at the Yodo River estuary within 2 hours and the Yodo River Large Weir within 2.5 hours after the earthquake.

Japan

Osaka

Kobe

JMA Magnitude : 8.4

Yodo River

Yodo River Large Weir

Osaka BayTonankaiNank

ai

Model of seismic source

(River flow : 196m3/s)


大阪市水道局 Chloride Ion Concentration

Yodo RiverKobe

Osaka

Maximum height of tsunami ( m )

Tsunami simulation Chloride ion concentration


(River flow : 196m3/s)

Upper FlowLower Flow(Osaka Bay)

Adjustment gate

Main gate

Okawa River


Kema Water Gate

KemaLock GateAdjustment gate

Intake point


大阪市水道局

0

1

2

3

4

0 100 200 300 400 500 600 700 800 900Flow m（ 3/ s）

0.90h

10

100

1000

10000

100000

0 100 200 300 400 500 600 700 800 900Flow (m3/ s)

Chl

orid

e io

nm

g/L

（）

Chloride ion

1020mg/ L

At Intake point, maximum concentration of Chloride ion is about 1,000 mg/L and maximum duration of concentration level exceeding water quality standards is about 1 hour.

Conclusion

Necessity of preparedness against tsunami

Tim

e o

f con

cen

trati

on

bein

g o

ver

sta

nd

ard

s (

h)


大阪市水道局








Tsunami




大阪市水道局

Making damage ratio equations

Collection and organization of data relevant to seismic damage of distribution pipes

STEP1

STEP2

Damage estimation of distribution pipes based on scenario earthquakes

STEP3

Investigation Flow Chart


大阪市水道局Points of the Review

Upgraded seismic damage data obtained from recent research on earthquake engineering

New estimation of the seismic damages of distribution pipes in liquefied area


大阪市水道局

◆ Previous research ◆

Data Utilized (1)

【 2km×2km data near seismometers （ JWWA1996 ， 1998 ）】= 29 areas


大阪市水道局

◆Present research◆

【 250m×250m data（ JWWA1996）】

Data Utilized (2)

Seismic Motion of Kobe Earthquake Reproduced

Damage Ratio of Distribution Pipes during Kobe Earthquake= about 4,800

meshes


大阪市水道局

Damage Ratio Equation

D0 : Average Ratio of Damage (points/km)PGV : Peak Ground Velocity (cm/s)a, b : Coefficient Constant

D = D0 x C1 x C2 　

D0 = a x (PGV - b)

D : Rate of Damage (points/km)C1 : Diameter Correction FactorC2 : Ground Correction Factor


大阪市水道局Classification of Liquefaction (1)Liquefaction Assessment

液状化状況 250mメッシュ ■ 非液状化 ■ 半液状化 ■ 液状化

Liquefaction Level as Classified by JWWA

PL-value calculated by Osaka Municipal Waterworks Bureau

Non-LiquefactionHalf-LiquefactionLiquefaction


大阪市水道局

◆Liquefied Ground◆

Relation between PL value and liquefied area

z

dzzfz0

)()(

PL value

Liquefa

ctio

n f

requ

ency

(%

) - : cumulo-probability density function

0 ,0

0 ,2

logexp

2

1)( 2

2

x

xx

xxf

Relation between PL value and liquefied area

PL valueLi

quefa

ctio

n f

requ

ency

(%

)

Classification of Liquefaction (2)


大阪市水道局

D0=0.0065 x (PGV－ 15)

D0=0.0153 x (PGV－ 15)

<Cast Iron Pipe>

<Ductile Iron Pipe>

Damage Ratio Equation (Non-Liquefied Ground)

0

1

2

0 50 100 150 200

【 Kobe earthquake 】

□ 2km mesh area data● 250m×250m data

【 function 】━ Osaka(2006)━ Osaka(1997)━ JWWA(1998)

0

1

2

3

4

0 50 100 150 200PGV (cm/s) PGV (cm/s)

Dam

age r

ati

o(p

oin

ts/k

m)

Dam

age r

ati

o(p

oin

ts/k

m)


大阪市水道局

Average Damage Ratio=2.56

Damage Ratio (Liquefied Ground)

Average Damage Ratio=4.00

[Reference]

<Cast Iron Pipe>

<Ductile Iron Pipe>

2.56

0

2

4

6

8

10

0 50 100 150 200

4

0

2

4

6

8

10

0 50 100 150 200

PGV (cm/s)PGV (cm/s)

Dam

age r

ati

o(p

oin

ts/k

m)

Dam

age r

ati

o(p

oin

ts/k

m)

【 Kobe earthquake 】

□ 2km mesh area data● 250m×250m data

【 function 】━ Osaka(2006)━ JWWA(1998)

[Reference]


大阪市水道局

Making damage ratio equations

Collection and organization of the data relevant to seismic damage of distribution pipes

STEP1

STEP2

Damage estimation of distribution pipes based on scenario earthquakes

STEP3

Investigation Flow Chart

Examining upper value of damage ratio

Examining value of damage ratio in liquefied ground


大阪市水道局Advanced Investigation Plan

Damage Estimation of Distribution Pipes

1

Simulation of Areas Affected by Water Suspension

2

Estimation of Seismic Damage to the Water Supply System

3

Examination of Effective Earthquake Countermeasures4


大阪市水道局Thank you for your attention!


大阪市水道局Vertical Two-Dimensional Box Model

Dep

th D

irectio

n

Flow Direction

Cell: Move of water and suspended solid is ignored


大阪市水道局Tsunami Simulation


大阪市水道局

Items of setting Setting value

Equations

Basic Equation Nonlinear Long Wave Equation

Difference SchemeStaggered Grid and Leap-Flog Method

Overflow Equation Honma Equation

Conditions

Fault Model Shown in Slide No.4

Grid Scale1350m→450m→150m→50m→25m→12.5m

Initial Tidal HeightH.W.L.（O.P.+2.10m）※T.P.±0.0m＝O.P.±0.0m＋ 1.30m

River Flow62m3/s, 196m3/s, 300m3/s, 500m3/s, 820m3/s, 3000m3/s

Gate HeightDecide the Gate Height every River Flow

Time Step Δt=0.3s

Reproduce Time 6hours, 12hours

Offshore Boundary Condition

Permeable Condition

Onshore Boundary Condition

Reflect Condition

Eddy Viscosity Coefficient AH=0.0

Roughness Coefficient n=0.025

Equations and Conditions (Tsunami Simulation)


大阪市水道局

Calculation Model

Vertical 2-D Box Model 　

Grid ScaleFlow Direction Dx = 200m

Depth Direction Dz = 1m

Time Step Dt = 1s 　

Velocity Distribution

Tsunami Run-up Uniform Velocity Profile

Other Logarithmic Velocity Profile

Overflow Equation

Honma's Equation 　

Pick-up Massof Bed Material

Applying the pick-up rate of mud and clay

Multiplying the mass fraction of clay component material in bed to pick-up mass

Bed material only pick-up from the river estuary to 11 km upper point

Manning's roughness

0.025

Fall Velocity Tsuruya's Equation

Equations and Conditions (Calculation of the chloride ion concentration)


大阪市水道局Seismic Motion & Damage of pipes

Seismic Motion of Kobe Earthquake Reproduced

Damage Ratio of Distribution Pipes during Kobe Earthquake

Strongest Shaking Area


大阪市水道局

PL Value

w(z) =10 – 0.5 x z

F = 1 – FL (FL<1.0) 0 ( FL>=1.0)

z :

Depth

fro

m s

urf

acePL =∫ F x w(z) dz

0

20


大阪市水道局Disaster Information Management System

Support for information to citizens and Osaka City Disaster Countermeasures Headquarters

Pipeline restoration

Seismic damage simulation function

Disaster Emergency Activities Information Management Functions

Integrated Management

Emergency water supply

Facility restoration

Documents

1 Earthquake Preparedness and Countermeasures in Osaka Municipal Waterworks Bureau Osaka Municipal Waterworks Bureau Kazuya YAMANO