West Palm Beach, Florida
Somerset Engineering Group provided construction engineering services for this design-build project to provide a temporary 1,200-foot long bascule bridge over the Intracoastal Waterway. The existing bridge was failing, and the Florida Department of Transportation's goal was to move traffic to the temporary bridge as quickly as possible.
For Somerset, the project involved relocating the four existing bascule leafs. The contractor wanted to float the bascules off their existing supports and land them on the newly constructed temporary piers. Each 320-ton leaf had to be floated with full counterweight still in place, cantilevered 26 feet over the side of the supporting barge. Since the barge was only 45-feet wide, Somerset performed ballasting and counterweighing calculations to maintain the barge level as it picked up the weight of the bridges. This resulted in 230 tons of concrete counterweight on the deck and up to 1070 tons of water ballasting.
Somerset also analyzed the barge structure for strength and concentrated load applications. The aggressive 12-month schedule was realized, with project completion in February 2000.