1915 Çanakkale Bridge A world record span suspension bridge · 1915 Çanakkale Bridge - Meeting the challenge 2 23 OCTOBER 2019 Teknologidagene 2019 ›Introduction to the bridge

23 OCTOBER 20191

Teknologidagene 2019

1915 Çanakkale BridgeA world record span suspension bridge

Inger B. Kroon, COWI

1915 Çanakkale Bridge - Meeting the challenge

23 OCTOBER 20192


› Introduction to the bridge

› Location

› Layout

› Setup and time schedule

› Analysis model

› Technical challenges and constraints

› Insight to the design process

› Bridge design – how and why

› Status

› Design status

› Construction status

Introduction – Location

23 OCTOBER 20193


› Western end of the Sea of Marmara (200km from Istanbul)

› Part of the Çanakkale-Tekirdağ-Kınalı-Balıkesir highway project

› Other major bridge references by COWI in the same area

23 OCTOBER 20194


Introduction - The project

23 OCTOBER 20195

Introduction - Bridge layout

23 OCTOBER 20196


› Main span 2023 m (World record)

› Side spans 770 m

› Approach bridges 365 m + 680 m

› Total length 4608 m

› Tower height 318 m

Introduction – Project setup

23 OCTOBER 20197


› Owner - KGM (Turkish Ministry of Traffic)

› Owners consultant - TTJV (Tekfen + T-Engineering)

› Concessionaire - ÇOK A.Ş

› Contractor - DLSY JV (Daelim, Limak, SK & Yapi Merkezi)

› Designer COWI with sub consultant PEC

› Independent Design Verifier (IDV) - Arup with sub consultant Aas Jacobsen

› Financing by 24 different banks and financial institutions from 10 different countries

Introduction – Design schedule

23 OCTOBER 20198


2017 2018 2019 2020 2021 2022JA

N

FEB

MAR

APR

MAY

JUN

JUL

AU

G

SEP

OCT

NO

V

DEC

JAN

FEB

MAR

APR

MAY

JUN

JUL

AU

G

SEP

OCT

NO

V

DEC

JAN

FEB

MAR

APR

MAY

JUN

JUL

AU

G

SEP

OCT

NO

V

DEC

JAN

FEB

MAR

APR

MAY

JUN

JUL

AU

G

SEP

OCT

NO

V

DEC

JAN

FEB

MAR

APR

MAY

JUN

JUL

AU

G

SEP

OCT

NO

V

DEC

JAN

FEB

MAR

APR

MAY

JUN

JUL

AU

G

SEP

OCT

NO

V

DEC

INITIAL DESIGN

DETAILED DESIGN

BRIDGE OPENING

Introduction – Construction schedule

23 OCTOBER 20199


Integrated Bridge Design & Analysis System (IBDAS)

23 OCTOBER 201910


› Global Analysis Model created in the structural design and analysis system IBDAS developed by COWI

› Creation of a parametric IBDAS model, using a combination of beam, shell and solid elements

› Local models have direct interface to global model and are activated inside global model obtaining easy loading and correct boundary conditions

IBDAS Global

Analysis model

Local Caisson models

Local AnchorBlock

models

Local Deck

models

IBDAS Global Analysis Model with local models

23 OCTOBER 201911


IBDAS Global Analysis Model with local models

23 OCTOBER 201912


Local fatigue model in IBDAS

23 OCTOBER 201913


Detailed FE-modelGlobal FE-model

Semi local shell model within the global model

Fine mesh size for fatigue verificationLocal model

Technical Challenges

23 OCTOBER 201914


› Ground conditions

› Seismic activity

› Live loads

› Ship impact

› Wind climate

› Schedule

› Design schedule

› Construction schedule

Weak soil at European and Asian shorelines

Ground conditions – Anchor blocks

23 OCTOBER 201915


Rock outcrop

Increase side spans to utilize Miocene rock

Concept – increased side span » tie-down system

23 OCTOBER 201916


Ground conditions – Tower foundation

23 OCTOBER 201917


EUROPEAN: Up to 25 m of soft Holocene clay deposits at 37 m water depth

ASIAN: Up to 14 m of Holocene sand and Pleistocene clay deposits at 45 m water depth

Seismic time history analyses

23 OCTOBER 201918


Input 1 Input 2 Input 3 Input 4 Input 5 Input 6

› 3 seismic events – FEE (125 year), SEE (975 year), NCE (2475 year)

› Individual input for 6 locations in 3 directions

› 7 sets of time series – see graph at tower for NCE

› Nonlinear element behaviour

› Hydraulic buffers at the towers

› Soil-structure interaction

› Wind bearings

Live load – Design criteria

23 OCTOBER 201919


› Loaded lengths < 200 m UDL = 81.8 kN/m

› Eurocode 1991-2 load model 1, 2 and 3

› Loaded lengths > 200 m UDL = 58.8 kN/m

› EN 1991-2 SE-NA (TRVK Bro 11 - taking effect of long loaded length into account)

Influence on normal force in hanger

Influence on normal force in main cable

Ship Collision Risk Analysis

23 OCTOBER 201920


Acceptance criteria of 10-4 per year

Design ship with static equivalent ship impact load of 370MN according to Ship Collision Risk Analysis

Ship impact dynamic analysis in global model

23 OCTOBER 201921


Ship impact – Towers

23 OCTOBER 201922


› Impact zone up to +29.5 m

› Semi-local and local impact governs tower design up to +29.5 m

› Skin plate thickness increased

› Horizontal stiffeners added to increase local bending resistance of skin plates

Tower foundations - Ship impact

23 OCTOBER 201923


› Global transverse ship impact force of 370 MN

› Strict design criteria introduced to achieve minimal damage of non-accessible parts of foundations under accidental loads

› Resulted in design challenges and detailing of reinforcement, e.g. diagonal bars in some walls and slabs

Asian caisson

Tower foundations - Ground improvement

23 OCTOBER 201924


› Tower caisson is placed on a 3 m thick gravel bed

› Ground improvement by Ø 2.5 m open ended steel inclusion piles socket into Miocene mudstone

› 192 piles below the European tower with lengths up to 46 m

› 165 piles below the Asian tower with lengths of 21 m

› Special ring structure and shear keys for load transfer from gravel into piles

› Piles reduce tower settlement and increase the lateral resistance

Miocene mudstone

Gravel

Aerodynamics – Wind climate & wind tunnel testing

23 OCTOBER 201925


› Analysis of wind data resulted in a basis wind speed of

Vb=29 m/s, giving V=46 m/s at deck level (+86.0)

› Wind tunnel tests located in:

› Canada (BLWTL)

› Deck section model, 1:60

› Deck section model, 1:30

› Denmark (FORCE)

› Tower section model, 1:80

› Full tower model, 1:225

› Tower erection stages in 1:225

› China (RCWE)

› Full bridge model in 1:190

› Full bridge erection stages in 1:190

Aerodynamics – Twin box girder

23 OCTOBER 201926


› Test of section models to optimize girder shape, gap width and wind screen

› Flutter stability is dependent on mean twist angle of bridge girder due to mean wind loading

› Critical wind speed 63/69/63 m/s must be secured:

› The girder section shape must be designed securing nose-up angles of 3-5° at wind speeds of about 70 m/s

Deck no Deck configuration a [] Vcr [m/s] Comment

A1 9m gap, inner web 14m wind screens

-1.50.0

+1.5

5366

>71

Failed

B3 9m gap, inner web 25m wind screens

-1.50.0

+1.5

64>78>69

OK

C3 9m gap, inner web 34m wind screens

-1.50.0

+1.5

65>77>69

OK -preferred

Aerodynamic – Full bridge model wind tunnel testing

23 OCTOBER 201927


› Aerodynamic stability was verified (with additionally damping of the towers) through wind tunnel tests of a 1:190 scale full aeroelastic model of the bridge.

Articulation

23 OCTOBER 201928


› Long span bridges giving large movements for in-service loads (traffic, temperature, wind) and seismic actions

› Hydraulic buffers at towers:

› restrain bridge deck for transient loads of passing trucks, buffeting wind

› reduction of movements giving extended lifetime of sliding elements

› allow free movement of deck for temperature and static traffic loads giving reduced reaction forces in the structures

› viscous damping during seismic events dissipating energy and controlling movements and forces

› Hydraulic end stops at towers:

› limit the expansion joint movements to a manageable level

Construction time – Towers

23 OCTOBER 201929


› Steel towers for fast erection

› Horizontal block joints with welded skin plates and bolted splice connections of longitudinal stiffeners

› Method enables fast construction with the possibility to erect new block before finalizing welding works

Osmangazi Bridge

Osmangazi Bridge

Osmangazi Bridge

Construction status – Tower foundation/Tower

23 OCTOBER 201930


Construction status – Anchor block/Approach

23 OCTOBER 201931


23 OCTOBER 201932

THANKS!

Documents

1915 Çanakkale Bridge A world record span suspension bridge · 1915 Çanakkale Bridge - Meeting the challenge 2 23 OCTOBER 2019 Teknologidagene 2019 ›Introduction to the bridge