|Replaced. I-10 westbound span opened eight days early, temporarily restoring damaged link across Lake Pontchartrain.|
The daily ride-by is one component of the Phase 3 maintenance contract that Mobile-based Volkert holds with the Louisiana Dept. of Transportation and Development. Engineers are happy to reach Phase 3an annually renewable contract to maintain, repair or replace the westbound spans temporary panels, which patch the gaps caused by Hurricane Katrina.
Katrina wrenched 435 twin span sections out of alignment. On Jan. 6, the 2-lane, 5.4-mile westbound span reopened eight days early, says LADOTD. New Orleans-based Boh Bros. Construction Co. LLC avoided a $10,000 daily disincentive on Phase 2 of the $35-million repair work, which included realigning 265 westbound span deck segments and filling in 26 gaps with prefabricated Acrow sections.
In Phase 1, finished in October, Boh reopened the eastbound span to two-way traffic by cannibalizing up to 64 spans from the westbound span and realigning 170 segments in a 24/7 contract that began Sept. 12, two weeks after Katrina. Bohs 17-day early completion on Phase 1 earned it the maximum bonus of $1.125 million (ENR 10/24/05 p. 7).
Acrow Corp. of America, Parsippany, N.J., produced the identical, prefabricated modular panels of hot-dipped galvanized steel. A dozen 65-ft-long panels comprise a 780-ft north section. Another 52 make up the 3,380-ft south section. Initially, LADOTD planned to borrowed Acrow spans from Florida, says Brian Buckel, LADOTD district engineer. But that would have limited traffic to one lane and required permits for traffic loads.
Volkert performed construction management on the two phases. Boh will now perform maintenance work to Volkerts specifications. In addition to the drive-bys, inspectors check underneath the span for damaged washers behind pins. Well have two inspectors working seven days a week, Havens says. Expected maintenance will include adjustment and replacement of bolts, nuts, pins and clips as the panels adjust to the traffic above.
We are building a database so we can monitor inspections, says Bob Larkin, Volkert project engineer. The amount of maintenance will be subject to variables such as average daily traffic, braking action, speeds and weather.
Havens, who also regularly inspects the Acrow bridge used on the hurricane-damaged Escambia Bay Bridge in Florida, predicts maintenance on the I-10 westbound span will be minimal. In the first week, we had a couple of pins try to back out and it was about a three- or four-minute tightening.
Despite the temporary moniker, the panels can last up to 45 years, says Mark Joosten, Acrow vice president. Its viewed as temporary because of the way its placed, being sort of [combined] with the existing bridge.
The temporary deck sits on strengthened pier caps, supported in part by 50-ton capacity screw jacks to minimize damage to bearings. The panels are coated with a high-grade, anti-skid epoxy, which presents another unknown. Its just epoxy, so if you have a lot of brakes on that deck, the friction will tear it up, says Havens. If it lasts 3 years, we will be in good shape. But LADOTD has ordered three extra Acrow panels for emergencies. If we do have a problem with the epoxy, or anything else, we have extra decks that can be installed within hours, says Havens.
Three years may be enough. This spring, LADOTD will let a three-year contract to build a $600-million new bridge to be be elevated 25 ft above the water, Buckel says. The Federal Highway Administration will fully fund it.
(Photos by Angelle Bergeron for ENR)hen Volkert & Associates senior inspector Larry Havens drives across the westbound span of New Orleans Interstate 10 bridge over Lake Pontchartrain, hes all earslistening for loose pins or clips in the steel-fabricated Acrow panels.