A 528 ft-wide, 2,650-ton steel truss span, supported by a U-shaped stability frame, is being readied for lift and placement on June 19 as part of a $1.2 billion widening project for the Huey P. Long Bridge in New Orleans, La.
The 75-year-old, 7,009-meter-long steel-truss railroad bridge has two rail tracks in the center and a pair of shoulderless highway lanes cantilevered off each side. The project is to widen the bridge to permit three lanes in each direction, plus shoulders. Work is being accomplished in four phases. Phase I, between April 2006 and May 2009 was to widen and strengthen the substructure and piers. Phase II covered railroad modifications performed between October 2006 and June 2008. Phase IV construction of new approaches and this one, Phase III, which covers the widening of the main span superstructure, began in June 2008 and is underway.
MTI, a joint venture of Massman Construction Co., Kansas City, Mo., Traylor Bros. Inc., Evansville, Ind. and IHI, Inc., New York, NY, won the $452.6-million, steel superstructure erection Phase III contract. The JV began erecting the truss on moored barges near the bridge last Oct. 27. It now sits ready to swing out into the Mississippi River and slip under the span supported on four barges, with three separator barges between them. It will be lifted 135 ft for installation.
MTI and consulting engineers HNTB Corporation devised the lift plan, which will be the first of three lifts in a span-by-span erection sequence.
The contractor plans to barge-position the truss on Friday, June 18. It will lift it into place the next day using four, 900-ton hydraulic strand jacks. Placement of the truss requires two days of road, river and rail traffic stoppages at one of the Mississippi River's most significant crossings.
