Permanent repairs to the Sanibel Causeway are substantially complete one year and four months after more than 6,000 Sanibel Island residents lost access to the mainland in the wake of Hurricane Ian. The joint venture team of Superior Construction and The de Moya Group, responsible for the work, say all travel lanes are now permanently open on the island off the southwest coast of Florida near Fort Myers .
“We have substantially completed the permanent repairs to the road, which includes everything within the white lines on the roadside,” says Senior Division Manager Ryan Hamrick and Group Area Manager De Moya , Toby Mazzoni, in a joint response to ENR.
In October 2022, 15 days of emergency work by Superior Construction and Ajax Paving made it possible to reopen the roadway. On September 8, 2023, Phase 2 began under Construcción Superior and Grupo de Moya, with the priority of further strengthening the roadway and protecting the roadway from future storms, which will be the focus of next year.
The scope of work, which Mazzoni says in a statement would normally take 18 months or more to complete, took 105 days. Project leaders attribute this speed to “phased design-build,” which allows for concurrent design and construction activities. While the Superior-de Moya JV team was completing the emergency work in October 2022, they were already meeting with the Florida Department of Transportation (FDOT) to discuss the design and construction of the next phase.
To complete the roadway reconstruction, the Sanibel crew demolished 35,000 square feet of existing asphalt and roadway base, 2,270 linear feet of concrete barrier wall and 4,500 linear feet of concrete decking and five slab areas of approach to the bridge, according to a statement. The roadway was also raised 2 feet.
The team is now focusing on work beyond the road shoulders, including resiliency measurement, and the team says Lee County is working with FDOT to restore the island’s parks and reopen the boat ramp nearby.
FDOT has approved a design for resiliency measures, including raising the levee 3 feet to protect the roadway from storm surge. On the ocean side, the seawall will be reinforced with layers of heavy shielding stone to provide protection against scour and breaking waves.
The bridge approaches, some of which collapsed during the storm, will be reinforced with a deep-foundation steel pile wall system, rather than mechanically stabilized earth (MSE) walls, which allows water escape through a drainage system.
“Almost every MSE wall system failed on the Sanibel causeway,” Hamrick and Mazzoni say. “The various steel pile wall systems are believed to prevent these same types of failures from occurring in the future.”
The roadway will be protected with a buried steel pile wall system that is capped with a concrete bulkhead and reinforced with a buried marine mattress and riprap stone. Sand was added on top to preserve the natural look of the beach.
Sanibel’s resilience features were designed based on data collected after Hurricane Ian made landfall. Each roadway varies in how it might react to a storm, project leaders say, so it’s critical to analyze each road on a case-by-case basis.
Hamrick and Mazzoni predict that despite the road elevation, water could still flow down the roadway in a storm comparable to Hurricane Ian. “But because of all these resiliency features, access won’t be cut off.”
