Critical surge barrier on New Orleans's eastern flank completed ahead of schedule
for sector gates, and those will provide +8 ft. of protection. “To try and determine whether that translates into 20-, 30- or 40-year levels of protection would be difficult to do because we have little spots we’d have to run through hydrology models,” Elmer says.
By 29 March, TMW was 94 percent complete on installation of batter piles, says Victor Zillmer, Corps resident manager on the IHNC surge barrier. “We have installed 67 percent (229) caps and 51 percent (3,918 ft.) of parapet wall,” Zillmer says. TMW had also installed 15 of 17 expansion joint pile pairs and 4 of 17 pairs of expansion joint caps. “We expect the braced wall to be substantially complete on 4 July,” Zillmer says.
In early April, Manson completed a 475-cu-yd concrete pour, the last large casting for the barge gate. Dredging east of the barge gate was 75 percent complete and expected to finish within the two weeks.
Rock and sand fill work is nearly complete and work is moving briskly on construction of tie-in concrete T-walls on both the north and south end of the project. Activities are expected to wrap up nearly every week, for the next few months, Zillmer says.
Bergeron notes that despite the pace and complexity, and with 32 cranes and 364 people working round the clock, the Corps reported only two lost-time incidents (one this fiscal year and one the last) for 1.4 million hours of work, says Sherry Scott, safety director for the Corps Hurricane Protection Office.
TMW’s three JV partners expect be finished, demobilized and offsite with all equipment by July, says Wayne Jones, TMW project manager. In early April, several of the larger cranes had already been moved dockside in preparation for demobilization.
“We will still be placing caps into the summer, and work on the gates will go on through the 2011 completion,” Hess says. “Obviously, until the whole thing is complete, there are still vulnerabilities out there,” he adds. “The job is not over until it’s over, and we’re keeping our eye on the prize. But we’re looking forward to finishing this up in short order and doing more work.”
Elsewhere in the web of linked waterways lacing the area, vulnerabilities still remain and contractors working to work to address them have much to do. At the north end of the IHNC, Alberici Constructors of Overland, Missouri, is just getting started on an estimated $155-million surge barrier at the Seabrook Bridge. The Corps awarded Alberici the $495,000 base portion of an early contractor involvement contract in October, and is working with Alberici to speed up installation of a cofferdam to provide some level of protection there.
“Surge coming into the lake will affect the interior of the canal,” Elmer says. The Corps, however, has strengthened canal walls with reinforcements including rip rap, sheet pile seepage cutoffs, relief wells and soil mixing. It hopes to have the cofferdam under construction by summer.
