Bridge

Seven Mile Bridge is the longest, continuous precast post-tensioned segmental concrete bridge in the world. In addition to its function as a main artery connecting the Florida mainland to the Keys, it also carries within its box girder body a 34-in. diameter water main. The bridge is part of a federally funded $179 million program directed by the Florida Department of Transportation to replace existing bridges in the Keys. Construction time was projected at three years, but due to the use of precast, segmental construction in assembly-line fashion, the job was completed six months ahead of schedule. An overhead gantry, specially designed for the job, was used to lift the preassembled 500-ton spans into place between pier segments. Thirty-six high-level piers were also pieced together on site using precast segments.