After successful implementation of several first-time innovations, the City of Key West now has two brand new operational bridges serving as the sole arteries to and from the City. Construction for the bridge rehabilitation and three-span replacement of the northbound and southbound bridges on US-1 over Cow Key Channel (Bridge Nos. 900086 & 900125) concluded November 2020. This project was proudly presented at the 2020 American Concrete Institute (ACI) Virtual Concrete Convention by our Chief Structural Engineer, Luis M. Vargas, PhD, PE, SE, who served as the Engineer of Record.
This innovative bridge rehabilitation, completed under our FDOT D6 Districtwide Bridge Repair/Rehabilitation Plans Preparation contract, replaced Spans 2, 3 and 4 using developmental Florida Slab Beams (FSB) with Carbon Fiber Reinforced Polymer (CFRP) prestressing and Glass Fiber Reinforced Polymer (GFRP) reinforcing. The first time a State Road bridge with FSB superstructure has utilized CFRP strands. This unique approach was highly beneficial as it eliminated concrete additives, waterproofing sealants, and corrosion concerns; reduced maintenance, labor & equipment costs; and ensures a longer service life.
Additionally, the required phased construction shifted existing traffic to a parallel bridge where heavy traffic conditions created an unacceptable level of service. Using an innovative traffic control approach and traffic simulation analysis, BPA successfully implemented a reversible traffic lane pattern on this project. Temporary delineators were used to shift the traffic patterns both in the morning (10 AM) and afternoon (2 PM) to maintain the existing number of lanes in each direction needed during peak traffic volumes. The reversible-lane configuration was developed in consultation with FDOT staff, local jurisdiction, and stakeholders. This is a first-time application of a reversible Temporary Traffic Control Plan using flush-mounted removeable delineators on an arterial facility in the State.
This unique project is also listed in the FDOT Transportation Innovation Initiative website.