VStructural, LLC (VSL) was awarded a contract to furnish and install a bonded post-tensioning system for the $660 million Huey P. Long bridge-widening
VStructural, LLC (VSL) was awarded a contract to furnish and install a bonded post-tensioning system for the $660 million Huey P. Long bridge-widening project in Jefferson Parish, La. Open since 1935, the bridge (spanning 8,076 feet by road and 22,996 feet by rail) will receive an additional travel lane, plus inside and outside shoulders on each side. Besides the new shoulders, three 11-ft. lanes in each direction comprising the completed bridge will provide a safer, more reliable Mississippi crossing. New roadway approaches with signalized intersections at Bridge City Avenue and Jefferson Highway also will be constructed as part of the four-phase project, considered vital to the recovery of the greater New Orleans area.
After starting this April, VSL’s services will be completed by year’s end. Phase 1 of the project began in April 2006, and its timetable calls for completion in 2012.
General contractor Massman Construction Co. hired VSL to supply post-tensioning materials and install 111 tons of 0.6-in.-diameter strand for the retrofit of piers used to widen the existing bridge. Post-tensioning was selected for this project because it easily accommodates the widening of existing piers, for which the method effectively provides circumferential reinforcement, observes VSL Project Manager Jeff Lungrin. In addition, horizontal post-tensioned tendons will be used as reinforcement at the ends of the piers where the thickness of the concrete will increase.
VSL Sales Engineer Gregory Hunsicker notes that the project also involves the use of VSL’s proprietary intermediate Type Z-anchor, which suits both circumferential and repair applications. For tendons whose ends cannot be secured using normal stressing anchorages, intermediate anchors provide a solution.
The use of Z-anchors eliminates the need for stressing buttresses, explains Hunsicker. A curved jack chair is used for Z-anchors to provide access for stressing. Additionally, a feature of the anchor head is movement of the anchor along the tendon axis during the stressing operation within a block-out. Following completion of post-tensioning, the block-out is filled with a concrete pour-back.
Prestressing steel lends itself to an efficient, durable and aesthetically attractive design, VSL representatives affirm, due to its (270-ksi) high strength and flexibility around the radii of pier corners. Says Hunsicker, The result is simplified concrete forming and improved structural aesthetics.
The Huey P. Long Bridge Widening Project is one of three major bridge projects included in the TIMED program Û reportedly the single largest transportation initiative in state history. VSL is also providing its SSI 2000 stay cable system for the John James Audubon Bridge, another TIMED job.