With an eye toward repairing a critical portion of Interstate 10, linking New Orleans to Baton Rouge and Texas, Louisiana Department of Transportation officials have awarded an emergency contract calling for a shuffling of precast roadway segments along a 5.4-mile twin bridge structure spanning Lake Ponchartrain. The $30.9 million contract requires crews from New Orleans' Boh Bros. Construction — working on a 24-hour/seven-day schedule — to use intact segments from the most damaged structure (westbound) as replacements for damaged portions on the more intact eastbound twin. The 300-ton-plus segments combine prestressed concrete I girders with integrally cast decks, all resting on pile bent-type piers. Hurricane Katrina's storm surge damaged or destroyed segments on both structures, leaving I-10 impassable. Most pile bents appear intact but have not been tested.

PHASED WORK

The first of the contract's three phases entails completion of repair and segment replacement on the eastbound span, which is scheduled to reopen by October 25 and create one lane for each direction of travel. A second phase calls for Boh Bros. crews to consolidate the remaining serviceable segments along one end of the second structure, and complete it with the erection of portable steel bridge panels and trusses from New Jersey-based Acrow Corp. of America. The second structure, scheduled for completion by January, will provide only one lane of traffic due to the portable units' load limits. The final phase will see the contractor handle maintenance for up to three years. Along with the contract awarding on Sept. 9, LaDOT announced plans to solicit bids early next year for a replacement I-10 Lake Ponchartrain twin structure, with three lanes in each direction.

The method of moving precast roadway segments between twin spans has most recently been deployed by Florida Department of Transportation officials, who sought rapid repair of twin I-10 Escambia Bay structures ravaged last year by Hurricane Ivan. After Katrina hit, FDOT officials assisted their Louisiana counterparts in determining the feasibility of moving segments between the Lake Ponchartrain crossing to restore limited I-10 service, and now are preparing to loan Acrow components sufficient for about 2,000 ft. of the Lake Ponchartrain crossing. FDOT also provided LaDOT shop drawings and contract language for use in preparing the $30.9 million contract as a design-build job. Florida officials chose to issue a contract for the Escambia Bay replacement twin bridge as design-build.

That fast track project is scheduled to open by December 2006, with pile driving now under way. The job will incorporate primarily 36-in. diameter prestressed cylinder square concrete piles; precast pile caps; 135-ft. prestressed bulb tee girders; and cast-in-place deck. The precast production is split between Tampa-based Standard Concrete Products and Gulf Coast Pre-Stress (GCP), whose plant is in Pass Christian, Miss., one of the areas hardest hit by Katrina. Clean up from the storm surge, and the restoring of power and water, had GCP re-starting production by month's end (note Editorial, page 4).

As work proceeds on I-10 in Louisiana and Florida, another key east-west thoroughfare — U.S. 90 along coastal Mississippi — will have some portions closed indefinitely. Primarily bridge sections of construction similar to those along Lake Ponchartrain, they sustained more severe damage from the Katrina storm surge.