“Providing safe access to Florida’s communities is at the heart of FDOT’s work,” said Janella Newsome, FDOT Director of Public Information, District One. “When Hurricane Ian damaged the Sanibel Causeway in September 2022 and destroyed Sanibel and Captiva islands’ connection to the mainland, FDOT was called to immediate action.”
State officials cleared bureaucratic hurdles, so FDOT and the contractor could focus on emergency repairs around the clock.
“With the contractor dedicated to this effort, road access to the islands for disaster responders and utility teams opened only seven days after commencement, with a temporary connection for residents and their contractors soon thereafter,” Newsome added.
The joint venture team of Superior Construction of Jacksonville, Florida, and The de Moya Group of Miami, Florida, completed the original repairs to the three-mile-long causeway within 15 days, working 24 hours a day, seven days per week. The storm had washed out two large sections of the causeway and damaged five approach slabs. The three concrete-girder bridges withstood the storm surge, and FDOT determined they were safe.
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“There was little to no damage to the bridge structures from [Hurricane] Ian,” said Toby Mazzoni, Area Manager for Superior Construction. “It was washouts and scours that had to be repaired.”
While working on the temporary repairs, the Superior-de Moya joint venture team started working on a design to construct a permanent causeway, according to Mazzoni. Kisinger Campo & Associates of Tampa, Florida, and Hardesty & Hanover of Port Charlotte, Florida, serve as the joint venture’s design team. “They designed based on data they received from [Hurricane] Ian,” Mazzoni said.
This project represents the state’s first phased design-build project.
“FDOT chose the phased design-build delivery approach for several reasons,” Newsome said. “Notably, we were able to bring a design-build team under contract within a very short time period, which was critical to restoring vehicle access to and from Sanibel Island within 15 days. Additionally, this approach fostered enhanced creativity and innovation needed for both the temporary and permanent repairs of the bridge approaches and causeway areas. It also promoted increased involvement and control from both FDOT and Lee County throughout the project, facilitating collaborative decision-making and better alignment with our project goals.”
Mazzoni credits a collaborative approach and cooperation with FDOT, Lee County, and other entities with allowing the team to finish on time. The team kept pushing forward to make that happen.
“We had a goal in mind, and we needed their help to make it,” Mazzoni said. “We ramped up resources.”
The partners worked as an integrated team and brought in multiple subcontractors. The team reached out to material suppliers for support and prompt deliveries.
“It worked smoothly,” said Ryan Hamrick, Division Manager with Superior. “It’s a testament to how well things can go when everyone gets on the same side of obstruction and pushes in the same direction. I cannot say enough about the support from FDOT, Lee County, and everyone involved within the area.”
The rush of traffic at the toll plaza heading to the islands resulted in delays and difficulties getting the materials needed for the project, as traffic backed up for miles. Numerous contractors are working to rebuild properties on the islands. About 6,000 people live on Sanibel and Captiva. The Superior-de Moya joint venture worked with Lee County to reverse-flow one of the eastbound lanes, to the islands, and allow trucks bringing supplies to the job to bypass the traffic backup getting to the island. The team used police escorts to ensure safety.
The team demolished 35,000 square yards of existing roadway asphalt and base, 2,270 linear feet of concrete barrier wall, and 4,500 linear feet of concrete coping. Then crews placed and graded 19,000 tons of shell base followed by 19,500 tons of asphalt.
In addition to the shell base and asphalt, the joint venture team built back 4,450 linear feet of retaining wall concrete cap, with 87,000 pounds of steel reinforcement, and 8,400 linear feet of island wall concrete cap, with 162,000 linear feet of fiber reinforcement. The five bridge approach slab areas, which were replaced, used 61,000 pounds of steel reinforcement.
At peak construction, the joint venture team had three pile-driving crews on land and in the water, four roadway earthwork crews, two storm drainage crews, six rebar-tying crews, eight concrete placement crews, three asphalt paving crews, and various other support resources.
Throughout construction, crews maintained two lanes of traffic, one in each direction. The Superior-de Moya joint venture divided the project into three traffic-control phases to remove and reconstruct the causeway. Any flagging operations that may have been needed to complete the work took place at night or on weekends only.
“Traffic is significant,” Mazzoni said. “Even with us not interfering with the road, there is still a lot of traffic.”
Project cost varies as the phased design-build project evolves. FDOT estimates it will reach about $285 million.
The team placed 25-foot to 30-foot-long steel sheets along the roadway and topped them with a concrete bulkhead. On the outside of the steel sheets, crews buried marine mattresses, a type of gabion basket filled with softball-sized stones, to further protect the roadway on the causeway islands. These marine mattresses are underground and will be covered with sand, leaving this area to look just like any other beach.
The original mechanically stabilized earth walls experienced significant failure during the 2022 storm. Building back new, the joint venture team drove steel sheets, including a steel king pile wall system, in its place, along with a 1,500 linear feet storm drainage system to assist in removing water from the roadway and to allow any storm surge to filter back to retention ponds before being discharged to the Gulf of Mexico.
“When the water comes running over the road, it will not scour the road,” Mazzoni said. “There will be roadway left when the waters reside.”
Seawalls had existed at the end of each of the three bridge structures, but they all failed during Hurricane Ian. The Superior-de Moya joint venture is raising those seawalls by three feet, using driven steel sheets with a concrete bulkhead on top. On the land side, it is reinforcing the walls with the marine mattresses covered with sand.
On the outside of the cantilever sheet pile walls, crews filled scour holes with limestone. Once filled, the team placed a 2.5-foot-thick layer of bank and shore riprap and topped it with a 5.6-foot layer of granite armor stone, sourced from Alabama and Georgia. The largest of the granite weighs up to 10,000 pounds. This stone is delivered to Fort Myers by rail and then trucked to the job site where it is barged to location.
“The stone will stick up out of the water, and people will be able to see it,” Mazzoni said.
The joint venture team used a marine operation to install the steel sheets, because the team could not bring in large enough cranes by land. At one point, there were three marine teams operating simultaneously. The team monitored turbidity, animals, sea grass, and other aspects of concern while working on the water.
Altogether, the team will install 163,000 square feet of retaining wall sheet piling, 64,000 square feet of king pile wall, and 183,000 square feet of island wall sheet piling.
Two of the rock operations are continuing in 2024, one placing the smaller stone and the other specialized to move one armor stone at a time into place. Most work will finish up mid-year with an expected completion at the end of this year.
“It means a lot to the community,” Mazzoni said. “This has been an experience-of-a-lifetime project.”
