On the first Friday of the new year eight days ahead of schedule the Louisiana Department of Transportation and Development (DOTD) reopened both westbound
On the first Friday of the new year Û eight days ahead of schedule Û the Louisiana Department of Transportation and Development (DOTD) reopened both westbound lanes of the Interstate 10 twin spans linking New Orleans and Slidell. After the official opening of westbound lanes, the eastbound left lane was closed for three days to allow re-striping of the bridge back to a one-way configuration.
A ribbon-cutting ceremony commemorated the reopening as another step toward recovery from the havoc wreaked by Hurricane Katrina. Speakers included Gov. Kathleen Babineaux Blanco, Acting Federal Highway Administrator J. Richard Capka, DOTD Secretary Johnny Bradberry, and Boh Bros. President Robert S. Boh, contractor for the work.
This bridge is a metaphor for Louisiana; it symbolizes our present and our future, said the governor. It was broken, but will return to functioning at capacity. And, when the new Îtwin spansÌ are built, capacity will grow by one-third with the addition of third lanes. Added Secretary Bradberry, The speedy completion of the twin-span repairs indicates DOTD’s commitment and desire to restore Louisiana’s infrastructure as soon as possible.
Repairs started on a 24-hour-a-day, seven-day-a-week schedule Sept. 12, two weeks after a storm surge during Hurricane Katrina knocked 435 pile bearing, precast roadway segments weighing 309 tons out of alignment. Sixty-four severely damaged segments had to be discarded. The project’s first phase, returning eastbound lanes to use in October, involved moving concrete spans from the westbound side to eastbound lanes to complete and repair gaps. Beating the Phase 1 deadline by 16 days, Boh Brothers earned a $1.1 million bonus (at the rate of $75,000 per day, with a 15-day cap). Nevertheless, savings of over $20 million from the estimated project cost were realized with a Phase 1 outlay of $31 million.
In Phase 2, performed concurrently, remaining undamaged panels on the ÎcannibalizedÌ bridge were shifted to one end of that span, and prefabricated bridge sections of hot-dipped galvanized steel were inserted into two sections extending 0.8 mile to form two lanes on a 24-ft.-wide deck. The entire structure is supported on the twin span’s preexisting pile bent pier foundations, confirmed by inspection to be structurally sound.
The project’s final Phase 3 involves an annually renewable contract to maintain, repair or replace the temporary metal panels. Accordingly, Boh Bros. will perform daily maintenance for up to three years on the portable bridge span components, until a new six-lane structure is built nearby. The cost of all three phases will total approximately $35 million, up $4.1 million following a change order in the repair contract to accommodate two westbound lanes instead of one.
A special traffic-management plan has been implemented for the repaired bridge, including a lower speed limit of 50 mph on the westbound side and 60 mph on the eastbound side; strategically placed variable message signs that can be programmed remotely to warn of fog and/or accidents; and, the operation of two Motorist Assistance Patrol vans from U.S. 11 to Oak Harbor/Eden Isle 16 hours a day, seven days a week. Barricading the north- and south-shore construction crossover locations, as well as the mid-span emergency crossover, with water-filled, movable barriers will permit access in case of major incidents or the need to divert traffic on a long-term basis.
Prior to Katrina, an average of nearly 55,000 vehicles a day traveled the 5.4 miles across Lake Pontchartrain on the twin spans. The daily traffic count on the two-lane, repaired bridge averaged 24,420 by the end of November, as excess traffic apparently used the U.S. 11 crossing, whose 6,700 pre-Katrina average daily traffic count escalated to 14,035.
According to Secretary Bradberry, DOTD plans to take bids in the first quarter of 2006 on a new twin-span bridge to replace the current twin spans. That new bridge will be a six-lane structure built at a higher elevation. Although finance arrangements have not yet been determined, the transportation department secretary notes, the state aims to have a contract in place by April for the project. At an anticipated cost of $500 million, construction of the new twin-span bridge is expected to take about three years.