Blackwater River Bridge

Florida Department of Transportation’s first major bridge design/build contract, the Blackwater River Bridge, was an emergency design/build bridge replacement of twin 3,000-ft. long bridges with one mile of approach roadway and associated civil work. FINLEY submitted a bid of $30.44M for the project with a 627 calendar-day construction schedule.

Continuous plate girder construction with typical approach spans of 184-ft. was utilized for the superstructure. The channel unit has a three span structure with spans of 184-ft., 220-ft., and 184-ft. The girder profile was constant with no haunched webs, and horizontal curvature was accommodated using heat-curved girders. Twin girder assemblies were constructed on barges, lifted into place, and field-spliced to adjacent assembles. Temporary shoring towers and bracing were not required. The substructure consists of pile foundations, supporting waterline footings and hammerhead piers which have been cast-in-place and sized for future widening.

Traylor was able to complete construction of the substructure for the Westbound Bridge within five months. Extensive use of Mechanically Stabilized Earth Walls was necessary due to limited right-of-way. HDPE (high density polyethylene) straps were utilized in lieu of metal straps due to the corrosive potential of the tidal surge associated with a hurricane.

The first bridge was completed and opened to traffic in the Fall of 1996. The two existing bridges were demolished and the second new bridge was completed in the summer of 1997.