ASPIRE is a quarterly magazine published by PCI in cooperation with the associations of the National Concrete Bridge Council. The editorial content focuses on the latest technology and key issues in the Concrete Bridge Industry.
Issue link: http://www.aspiremagazinebyengineers.com/i/768999
PROJECT Long Key Bridge Pier Replacement V-pier replacement at 12 expansion joints by Dennis Fernandez, Florida Department of Transportation and Dr. Luis Vargas, Bolton Perez & Associates The first real bridge construction across the Florida Keys began in April 1905 when a 100-ft-long drawbridge was put in place. The first important long bridge was the Old Long Key Bridge, which consisted of 2.7 miles of concrete arches. This was one of the first major trestle-type structures completed and it withstood, without damage, the most disastrous storm on record in this part of the state, the Hurricane of 1909. The Old Long Key Bridge was removed from the state highway system in 1982 after the existing Long Key Bridge was opened. The existing Long Key Bridge is located in the Florida Keys (MM 63.2) and was completed in 1981. It was the first post-tensioned concrete segmental bridge built in the state of Florida. At 12,152 ft long, it serves as the only route into the Florida Keys. Existing Bridge Description The bridge was the first precast concrete, segmental box-girder bridge in the world to be erected using the span-by-span method of construction with external tendons. The bridge is prestressed longitudinally using posttensioned external tendons and the deck is transversely prestressed using pretensioned strands. The bridge was constructed using the dry joint construction method. All nonprestressed steel reinforcement is epoxy-coated. There are 13 continuous units, with each unit consisting of seven or eight spans. A typical unit is 944 ft long between expansion joints. Movement was accommodated at the base of the existing V-piers. Thermal, creep, and shrinkage movements take place about the neutral point at the middle pier of each eight-span unit. The bridge foundations are drilled shafts, designed to carry longitudinal forces exerted by the stiffness of the bearings, V-piers, and superstructure interaction. The bridge works as a fully integrated system. PROFILE LONG KEY BRIDGE PIER REPLACEMENT / MONROE COUNTY, FLORIDA PIER REPLACEMENT DESIGN ENGINEER: HDR, Miami, Fla. PIER REPLACEMENT DESIGN PEER REVIEW: Corven Engineering Inc., Tallahassee, Fla. PRIME CONTRACTOR: Johnson Brothers Construction, Lithia, Fla. PRECASTER: Standard Concrete, Tampa, Fla.—a PCI-certified producer CONTRACTOR’S SPECIALTY ENGINEER (DESIGN AND DETAILING OF FALSEWORK, MEANS AND METHODS): A2B Engineering LLC, Tampa, Fla. CONTRACTOR’S SPECIALTY ENGINEER (FIELD SERVICES): BMA Consulting Engineers, Hollywood, Fla. CONSTRUCTION INSPECTION: WSP|Parsons Brinckerhoff, Tampa, Fla.