1. 3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION1
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
2. 3 AEPTEMBER 2014
COWI POWERPOINT PRESENTATION2
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. 3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION3
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
4. 3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION4
Design concept
› Form and functionality unique
› Fantasy concept
› Like art
› Lighting and illustration to become
landmark for Lusail in Qatar
= The challenge was set
5. 3 SEPYEMBER 2014
COWI POWERPOINT PRESENTATION5
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
6. 3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION6
Design
› Composite bridge deck with closed steel box
› Steel box and main cable corrosion
protected by dehumidification system
Self anchored suspension bridges
7. 3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION7
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
8. 3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION8
Design
› Main cable 7 locked coil strands Ø140,
13900mm^2, min 18,7MN
› Main cable Ø424 dehumidification system
Cable system
9. 3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION9
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
10. 3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION10
Design
› Cables are anchored at pylon ring.
› Anchor saddle would be long is not
anchored individual
Anchor of Main cable at pylon
11. 3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION11
Design
› Hangers pre-fabricated locked coil
strands Ø70, 3390mm^2 and min.
strength of 4.8MN
› Hangers protected by HDPE pipe
Hangers
12. 3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION12
Design
› Cable clamps design very compact and
unique visual from the road.
Cable clamps
13. 3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION13
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
14. 3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION14
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
insitupre-fab
pre-fab insitu
15. 3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION15
Design
› Box girder closed
› small cross girders per 6m max height 2,74m and width 1.0m
Steel girder
16. 3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION16
Design
› Utilities running in the girders
› hence relative large opening
Steel girder
17. 3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION17
Design
› Cross girder per 6m for the hangers
› No cross girders between the pylon legs
Cross girder
no cross girders
18. 3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION18
Design
› Hammerhead in concrete
› Connecting bridge deck with pylon legs
and with the pylon ring
Connection bridge deck and pylon
19. 3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION19
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
20. 3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION20
Design
› Pylon steel strengthened with stiffeners
Pylon ring
21. 3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION21
Design
› 6+8 cables between the pylon steel ring
and pylon pier
Concrete part of pylon ring
22. 3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION22
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
23. 3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION23
Design
› All closed steel areas will
corrosion protected by
dehumidification
› One system for bridge
girder, pylon and main
cable
Dehumidification system
24. 3 SEPTEMBER 2014
COWI POWERPOINT PRESENTATION24
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
