The Florida Dept. of Transportation (FDOT) awarded the design-build contract in June 2018, with work wrapping up on the bridge in May 2022. The bridge is founded on precast piles with water-level foundations featuring architectural columns and caps, with Florida I-Beam girders, cast-in-place decks, barrier walls and a fender system completing the structural work.

Photo courtesy American Bridge Co.

Apart from the bridge, the project team resurfaced 1.7 miles of SR 679 and constructed a roundabout, lighting, signage, an Intelligent Transportation System package and retention ponds. The existing bascule bridge was removed via explosive and piece-by-piece demolition.

The largest challenges, according to the project team, were the environmental impacts to residents, motorists, anglers and cyclists; and building so close to the existing bridge, while tying into nearby interchanges with the grade, while maintaining the 65-ft clearance over the channel.

The American Bridge team reduced the temporary trestle by more than 75% from concept plans to minimize temporary seagrass impacts and reduced the overall bridge length and increased span length to lessen pier structures, bearings and expansion joints, minimizing the long-term maintenance cost.

Two-stage, cast-in-place walls met both required project aesthetics and traffic phasing, while deep foundations reduced the potential for cracking due to settlement, and other aspects helped to extend the bridge’s lifespan beyond the 75-year design life requirement. To maximize that lifespan, American Bridge used a glass fiber reinforced polymer rebar in the seawalls. It doesn’t corrode, and seawall caps will remain highly serviceable for FDOT.

The project team also worked to meet the community and FDOT’s vision, including shortening the bridge by almost 300 feet and lowering the profile, and providing a more symmetrical and aesthetically pleasing view for mariners traveling through the channel, residents and visitors to Fort DeSoto Park.