The Carolina Bays Parkway (SC 31) is a major mobility corridor in Horry County, South Carolina, serving as a 30.6‑mile alternative to the heavily traveled routes leading toward Myrtle Beach. As part of a four‑mile extension of the parkway, STV provided design services for a new six‑lane bridge that spans the Atlantic Intracoastal Waterway. The structure improves mobility between North and South Horry County while supporting the region’s long‑term growth and tourism demands. Because the corridor is subject to frequent seismic activity and includes environmentally sensitive wetlands, the bridge design required careful engineering and environmental stewardship.
What challenges did STV address?
The project corridor sits within one of the East Coast’s most active seismic zones, requiring a resilient bridge design capable of withstanding significant seismic forces. Wetlands along the Intracoastal Waterway also limited ground disturbance and construction access. The project needed to balance structural demands, environmental permitting, waterway navigation and long‑span constructability while minimizing impacts to sensitive ecosystems.
What solutions did STV deliver?
As a subconsultant to Civil Engineering Consultant Services, STV provided structural design services, wetlands delineation and U.S. Coast Guard permitting support. The team designed a 28-span, 3,632.5-foot bridge with spans up to 310 feet to reduce the number of in-water supports and protect the surrounding wetlands. STV used advanced software to perform multimodal and push‑over seismic analyses, enabling engineers to evaluate how the bridge would perform during different seismic events and optimize its resilience.
How does this project benefit the community?
The upgraded parkway offers safer, more efficient travel between rapidly developing areas of Horry County. The resilient design protects mobility during seismic events, while the long‑span configuration preserves the natural environment and minimizes impacts to navigation and wetlands. The bridge strengthens regional connectivity and supports economic growth for residents, businesses and visitors.
Key stats and accolades
- 3,632.5‑foot‑long, 28‑span bridge
- Long spans up to 310 feet to minimize wetland impacts
- Advanced seismic modeling and push‑over analysis
- U.S. Coast Guard permitting supported by STV
