Replacing the Stay Cables on the Hale Boggs Memorial Bridge (I L li ...

David Coulsey
Kiewit Louisiana Co.
<strong>Replacing</strong> <strong>the</strong> <strong>Stay</strong> <strong>Cables</strong> on <strong>the</strong>
Hale Boggs Memorial Bridge
(I (I‐310‐Luling) L li )
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Luling u gBridge dge Project– oject By y <strong>the</strong> t eNumbers u be s
Original Construction Completion …. 1983
Vehicles Vhil Crossing C i Per P Day D ….. 45,000
Span Length…… 2,225 ft
Pylon Height Height……. 400 ft
Number of <strong>Stay</strong> <strong>Cables</strong> to Replace…….. 72 ea
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Luling u gBridge dge Project oject ‐ Why y We’re e eHere ee
Corrosion of
Existing <strong>Cables</strong>
All C<strong>Cables</strong> bl h have
Damage
39 of 72 rated
Critical
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Existing Cable <strong>Stay</strong>s
Parallel wire system
Prescon anchorage
111‐307 ¼” dia. 270ksi bare wire
Individually “button‐headed”
Grout filled stay pipe
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Deck Anchorage
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New Cable <strong>Stay</strong>s
VSL SSI2000 Parallel Strand System
Multiple corrosion barriers
- Individually greased and shea<strong>the</strong>d 0.62” strand
- HDPE <strong>Stay</strong> pipe
Stringent testing requirements
Strand by strand replaceability
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Cable Operations Sequence
Install Temporary <strong>Stay</strong> <strong>Cables</strong>
Lift‐Off, De‐Stress, & Remove Existing <strong>Stay</strong>s
Modify Existing Structure @ Anchor Locations
Install New Cable <strong>Stay</strong>s
De‐Stress, Jump, & Re‐Install Temporary <strong>Stay</strong>s
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1 & 6 400 11,132 132
1 & 5 280 1,025
2 & 5 260 862
3 & 4 260 610
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De‐Stress & Lower Existing g <strong>Stay</strong>s y
Existing stay cables de‐stressed in a pair
KLC required to find <strong>the</strong> force in <strong>the</strong> existing stay cables
Four phases to <strong>the</strong> De‐Stress & Lower Operation:
1. Lift Off & De‐Stress <strong>Stay</strong>
2. Lower <strong>Stay</strong> from <strong>the</strong> Pylon
33. Cut <strong>Stay</strong> Cable
4. Load Cable for Scrap
Backspan
Mainspan
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Composite Photo of Deck Level Anchor with De-
Tensioning Adapter Socket Installed
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Install New <strong>Stay</strong>s y
Install New <strong>Stay</strong> Anchorages/Components
Weld HDPE <strong>Stay</strong> Pipe
Hoist Pipe
Install & Stress Strand
Install Dampers and close up
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New e <strong>Stay</strong> Components Co po e ts – Deck ec Level ee
Anchor Chair Exit Pipe
& Anchor
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New e <strong>Stay</strong> Components– Co po e ts Pylon yo Level ee
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Installed Pylon Anchor
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New <strong>Stay</strong> y Components p – HDPE Pipe p Weld
Fuse/Weld pipes toge<strong>the</strong>r with Butt Fusion Hydro‐
Electric Machine
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New <strong>Stay</strong>‐ Pipe Hoist
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QUESTIONS ?
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