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TRANSCRIPT
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
COWI POWERPOINT PRESENTATION 2
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
COWI POWERPOINT PRESENTATION 3
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
COWI POWERPOINT PRESENTATION 4
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
COWI POWERPOINT PRESENTATION 5
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
COWI POWERPOINT PRESENTATION 6
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
COWI POWERPOINT PRESENTATION 7
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
COWI POWERPOINT PRESENTATION 8
Design
› Main cable 7 locked coil strands Ø140, 13900mm^2, min 18,7MN
› Main cable Ø424 dehumidification system
Cable system
3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION 9
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
COWI POWERPOINT PRESENTATION 10
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
COWI POWERPOINT PRESENTATION 11
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
COWI POWERPOINT PRESENTATION 12
Design
› Cable clamps design very compact and unique visual from the road.
Cable clamps
3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION 13
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
COWI POWERPOINT PRESENTATION 14
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
COWI POWERPOINT PRESENTATION 15
Design
› Box girder closed
› small cross girders per 6m max height 2,74m and width 1.0m
Steel girder
3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION 16
Design
› Utilities running in the girders
› hence relative large opening
Steel girder
3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION 17
Design
› Cross girder per 6m for the hangers
› No cross girders between the pylon legs
Cross girder
no cross girders
3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION 18
Design
› Hammerhead in concrete
› Connecting bridge deck with pylon legs and with the pylon ring
Connection bridge deck and pylon
3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION 19
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
COWI POWERPOINT PRESENTATION 20
Design
› Pylon steel strengthened with stiffeners
Pylon ring
3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION 21
Design
› 6+8 cables between the pylon steel ring and pylon pier
Concrete part of pylon ring
3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION 22
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
COWI POWERPOINT PRESENTATION 23
Design
› All closed steel areas will corrosion protected by dehumidification
› One system for bridge girder, pylon and main cable
Dehumidification system
3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION 24
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