nvf annual bridge conference 2014 unique bridges in · pdf filenvf annual bridge conference...

3 SEPTEMBER 2014

COWI POWERPOINT PRESENTATION 1

NVF Annual Bridge Conference 2014

Unique bridges in Qatar

Jesber Rasmussen, Chief Project Manager, COWI A/S

Agenda: • Client's Expectations • COWI's design • Contractors

construction sequence • Photos from the

construction

3 AEPTEMBER 2014


Client's expectations

› New township in Doha in Qatar to 200.000 residents

› Marinas

› Business center

› Entertainment

› Beaches

› Hotels

› 5 billion dollar projects

› 9 marine bridges

› Two of the bridges needed to be very unique

Project description

3 SEPTEMBER 2014


Client's expectations

› Cable Stayed landmark

› Arch bridge landmark

› Suspension bridge landmark

Client chose the suspension bridge

Because:

› First of its kind in the world

› A true landmark for Lusail

› Circle could resemble the Q in Qutar

› Circle represent the sun as the source of life

Concepts developed together with

Dissing+Weitling

3 SEPTEMBER 2014


Design concept

› Form and functionality unique

› Fantasy concept

› Like art

› Lighting and illustration to become landmark for Lusail in Qatar

= The challenge was set

3 SEPYEMBER 2014


Design

› Suspension bridge concept with app. 200m bridge lengths

› Self anchored suspension bridges with one cable plan

› Cross girders and hangers per 6m

› Ring diameter of 50m produced in high strength steel over the deck and high strength concrete under the deck

Self anchored suspension bridges

3 SEPTEMBER 2014


Design

› Composite bridge deck with closed steel box

› Steel box and main cable corrosion protected by dehumidification system

Self anchored suspension bridges

3 SEPTEMBER 2014


Design

› Mono cable

› Cable anchored at ring and at bridge ends and down to the anchor block

› Like a two tower suspension bridge with double length

Main cable

3 SEPTEMBER 2014


Design

› Main cable 7 locked coil strands Ø140, 13900mm^2, min 18,7MN

› Main cable Ø424 dehumidification system

Cable system

3 SEPTEMBER 2014


Design

› Bridge self anchored partly

› Main span fully anchored for main span

› Side span anchored at bridge deck and at the anchor block

Anchor of Main cable at bridge ends

Anchored down due to uplift

3 SEPTEMBER 2014


Design

› Cables are anchored at pylon ring.

› Anchor saddle would be long is not anchored individual

Anchor of Main cable at pylon

3 SEPTEMBER 2014


Design

› Hangers pre-fabricated locked coil strands Ø70, 3390mm^2 and min. strength of 4.8MN

› Hangers protected by HDPE pipe

Hangers

3 SEPTEMBER 2014


Design

› Cable clamps design very compact and unique visual from the road.

Cable clamps

3 SEPTEMBER 2014


Design

› Composite bridge deck with 250mm concrete deck for weight and stiffness for cable system

› Max deformation 1/400*span

› Single cable plan require torsion stiffness = closed box girder

› Pre-fab + insitu deck

Bridge deck

3 SEPTEMBER 2014


Design

› Two precast elements used

› Between the pylon legs insitu concrete steel plate under for strengthening

› At bridge end in situ concrete because of joints and steel plate under the deck for strengthening

Bridge deck

side span abutment

Pylon leg Pylon leg

main span abutment

insitu insitu pre-fab

pre-fab insitu

3 SEPTEMBER 2014


Design

› Box girder closed

› small cross girders per 6m max height 2,74m and width 1.0m

Steel girder

3 SEPTEMBER 2014


Design

› Utilities running in the girders

› hence relative large opening

Steel girder

3 SEPTEMBER 2014


Design

› Cross girder per 6m for the hangers

› No cross girders between the pylon legs

Cross girder

no cross girders

3 SEPTEMBER 2014


Design

› Hammerhead in concrete

› Connecting bridge deck with pylon legs and with the pylon ring

Connection bridge deck and pylon

3 SEPTEMBER 2014


Design

› Pylon ring 50m dia.

› Pylon in high strength steel above bridge deck and pre stressing high strength concrete below bridge deck

› Foundation on bored piles

Pylon ring

3 SEPTEMBER 2014


Design

› Pylon steel strengthened with stiffeners

Pylon ring

3 SEPTEMBER 2014


Design

› 6+8 cables between the pylon steel ring and pylon pier

Concrete part of pylon ring

3 SEPTEMBER 2014


Design

› Post-tensioned anchor block

› 5 strands from main anchored in anchor block 2 strands anchored in the superstructure girder

› 7 strands anchored in the superstructure at the abutment

Anchor block and abutment

3 SEPTEMBER 2014


Design

› All closed steel areas will corrosion protected by dehumidification

› One system for bridge girder, pylon and main cable

Dehumidification system

3 SEPTEMBER 2014


Construction sequence

1. Widen earth bridge/excavation

2. Piling and pile cap construction

3. Substructure construction

4. Backfill and gantry crane installation

5. Bent system-side span construction

6. Pylon & main span erection

7. CIP deck cast

8. Cable Erection

Construction

3 SEPTEMBER 2014


Photos

30 AUGUST 2014


Completed bridge

3 SEPTEMBER 2014


Thank you

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