The 30.6-mile Carolina Bays Parkway (SC 31) in South Carolina runs parallel to the Intracoastal Waterway and allows drivers traveling between North and South Horry County to easily circumvent motorists headed towards Myrtle Beach, a popular destination in the region. As part of a four-mile extension of the roadway, a new six-lane bridge was erected, with three lanes in each direction. The structure needed to withstand the region’s frequent seismic activity, while avoiding any impacts with surrounding wetlands.  STV, as a subconsultant to the Civil Engineering Consultant Services, provided design services for the new bridge. The firm also performed wetlands delineation services, and led the project permitting component on behalf of the U.S. Coast Guard.

The new bridge is a 28-span, 3,632.5-foot-long structure. STV’s design integrated long spans up to 310 feet to preserve durability and minimize construction impacts to the Atlantic Intracoastal Waterways. The firm utilized software to perform multimodal and push-over seismic analyses that helped evaluate bridge performance during an earthquake.