South West 1st Street Bridge Replacement

Miami, Fla.

Award of Merit, Highway/Bridge

Submitted By: Hardesty & Hanover

Owner: Florida Department of Transportation Division 6

Lead Design Firm: Hardesty & Hanover

General Contractor: GLF Construction Corporation

Subcontractors: HDR Engineering, Sakoian International, Geosol, Media Relations, Synterra, Sea Diversified

The new 507-ft-long South West 1st Street bridge provides a stylish connection between downtown Miami and the Little Havana neighborhood, with a 315-ft double-leaf bascule span across the 125-ft-wide Miami River navigation channel. Drawing on input from a community advisory committee, the bridge’s art deco-themed aesthetics with local architecture and those of the predecessor crossing, built in the late 1920s. The project also included two new approach spans providing 18 ft of clearance over North River and South River Drives, new seawalls along the river, incorporation of Miami Greenway riverwalks, an improved stormwater drainage system, decorative street lighting and an exclusive bicycle lane.

Constructing this signature structure required extensive coordination given the volume of cargo traffic on the river, as well as the constraints of a busy urban area adjacent to Interstate 95, including multiple other building projects nearby. Cofferdams were built to allow installation of prestressed driven concrete piles into preformed holes.

Given the close proximity of the Miami River Inn, the city’s oldest hotel, micropiles were utilized for the foundation of the west bridge abutment. To further minimize river traffic disruptions, precast concrete panels were utilized during placement of the bascule span’s exodermic deck, which provides a safer and quieter riding surface while also protecting the steel superstructure.

Both motorists and river vessels can count of reliable performance of the 4-million-lb bascule span, thanks to a robust gear train driven by 150-hp motors equipped with a variable frequency controller and a combination of relay and PLC control logic. An innovative barrier-mounted lock system will facilitate more efficient bascule span maintenance.