The Challenge
Design and related services were needed for the Thompson Road Extension (LA 57 to LA 56) – Phase II Roadway Paving and Bridge for the East Houma Surge Levee project. This unique project serves as both a public roadway and a flood protection levee. Multiple challenges existed, including the bridge crossing Bayou Chauvin, which was required to be near a large pump station discharge. In addition, the bridge approaches were predicted to have an excessive amount of long-term settlement due to a deep layer of undrained soils below the area. Another design challenge was the required roadway crossing of Bayou Grand Caillou, which is a main drainage artery for the east side of the City of Houma.
The Solution
TBS performed topographic surveying, roadway and bridge design, major utility relocation design and coordination, and construction administration and inspection for the 2.7 miles of two-lane highway, which included a 180-foot-long bridge and turn lane improvements on existing roadways. Notable design features include an armored channel bottom to withstand the discharge of the adjacent pump station and implementation of a wick drain settlement program to minimize bridge end bent settlement. To cross Bayou Grand Caillou, TBS designed a double-barrel box culvert system that utilizes two six-foot-by-six-foot sluice gates for drainage control. During construction, TBS administered and oversaw bypass pumping plans for both the Bayou Chauvin Bridge and the Bayou Grand Caillou box culvert installations to ensure upstream flooding would not occur during the project.