US 98 Pearl River Bridge Replacement

Garver developed hydraulic bridge recommendations to replace both the existing eastbound and westbound bridges on US 98 over the Pearl River near Columbia, Mississippi. Due to the hydraulic complexity of the wide floodplain, meandering river channel, and multiple bridges in the vicinity of the main channel bridges, Garver developed an SMS/SRH-2D two-dimensional (2D) hydraulic model. Garver initially developed hydraulic bridge recommendations to replace only the eastbound bridge, which was built in the 1930s. Subsequently, an approximate 35-year flood event occurred, which caused approximately 15 feet of scour at the westbound bridge and resulting in a scour critical condition. 

Garver then developed hydraulic bridge recommendations to replace the westbound bridge. In addition to the 2D hydraulic modeling, a one-dimensional (1D) HEC-RAS model was used to analyze the FEMA Zone AE regulatory floodplain and floodway, and prepare the necessary No-Rise/No-Impact certification. Bridge scour analyses, stream and scour countermeasure design, a hydraulic report, and preliminary bridge layout drawings were provided.