The Bear Cut Bridge and West Bridges is part of the Rickenbacker Causeway that connects Key Biscayne and Miami in Florida. The Rickenbacker Causeway is named after Eddie Rickenbacker, a WWI vet and founder of Eastern Air Lines. The original work on the bridges began in 1926, and in 1947 it was officially opened to traffic. Not only does the Bear Cut Bridge connect the southernmost island of Key Biscayne to Miami-Dade County, Fla., but it is a popular route for avid cyclists.
Over time, the harsh coastal environment of Biscayne Bay had severely deteriorated the superstructure. In 2012, the discovery of corroded steel support girders mandated the emergency replacement of the bridges.
Hardesty & Hanover and Kiewit Infrastructure South teamed together to provide design-build services for the design, demolition, and construction of a new superstructure for the Bear Cut and West Bridges. Kiewit Infrastructure South invited two construction materials suppliers, including MAPEI to conduct a field trial with the existing conditions at the jobsite. MAPEI was chosen to complete the bridge restoration based on several product performance advantages. Planitop X, a fast-setting, fiber-reinforced repair mortar, offers high early strength and very low permeability to chlorides. Planitop 15, a form-and-pour repair mortar, was chosen because of its mechanical properties as well as its ability to flow long distances without segregating.
Premier Corrosion Protection was the contractor of choice for the rehabilitation of the bridge and executed the structural repairs of delaminated areas on pier caps and columns. The new superstructure consists of modified pre-stressed concrete AASHTO Type II Girders. The girders were modified in height so that the existing bridge profile could be preserved. In addition, the new concrete superstructure had to maintain the original dead load so that the existing substructure would not be overstressed. The design and construction was completed within 16 months. The repairs to the bridge are estimated to extend the life of the Bear Cut Bridge by 40 years.
In 2014, the Bear Cut and West Bridges, Key Biscayne, Fla., project was awarded “Best Project—Renovation/Rehabilitation/ Restoration” and the “Honor Award—Infrastructure by the Design-Build Institute of America (DBIA) Southeast Region”. In 2015, the project was named “Project of the Year (III)” by the Cuban-American Association of Civil Engineers.
Construction on the bridge was officially completed in August 2014.