H&H provided emergency engineering design services for the restoration of the Sanibel Causeway after it sustained extensive damage during Hurricane Ian in 2022. Structural failures of the existing mechanically stabilized earth (MSE) retaining walls, anchored concrete sheet pile seawalls along the bridge approaches, and multiple full breaches of the earthen causeway and roadways between the bridges prevented vehicle access to Sanibel Island.
The project was delivered under an emergency progressive design-build contract executed by a joint venture, with H&H serving as a subconsultant providing engineering design services.
During the initial emergency phase, H&H developed temporary repair designs that restored emergency vehicle access to Sanibel Island just six days after receiving Notice-to-Proceed. More than 1,000 truckloads of earth fill were placed along the failed retaining walls, with temporary sheet pile walls installed to stabilize the slopes. Breaches in the causeway were filled, and the repairs were armored with limestone riprap to maintain the integrity of the temporary embankments and provide safe public access until permanent repairs could be completed.
The final phase included the design and construction of permanent steel sheet pile walls and steel combination walls with limestone riprap scour countermeasures engineered to withstand the aggressive marine environment and improve resilience against future coastal storm events. To protect the earthen causeway and roadway from future scour and undermining, the permanent design incorporated buried steel sheet pile walls and marine mattresses.
H&H collaborated closely with the contractor joint venture team, FDOT District 1 and Central Office, and the design partner to evaluate the causes of the damage and develop both the temporary and permanent repair solutions. The project successfully restored access to Sanibel Island while delivering long-term infrastructure improvements designed to enhance durability and resilience.
Project Accolades
