The Bear Cut Bridge of the Rickenbacker Causeway, which connects Miami to Key Biscayne, requires reconstruction and widening and must be completed in time for a major sports event to be staged in March 2014. Armando Raul Rodriguez, Miami-Dade County Photographer
The crossing that is critical to the Florida Keys is being widened and strengthened to help it withstand severe storms.
June 11, 2013—Under a “very aggressive” construction schedule that has been imposed to accommodate a high-profile sporting event, the Florida offices of the construction firm Kiewit, which is based in Omaha, Nebraska, have begun major repair and rehabilitation work on two spans of the Rickenbacker Causeway, which traverses Biscayne Bay to connect the city of Miami to the barrier islands of Virginia Key and Key Biscayne.
The 66-year-old Rickenbacker Causeway is 5.4 mi long and is named for the World War I flying ace Eddie Rickenbacker, who became chairman of the board of Eastern Air Lines. It features three named bridges: the William Powell, the Bear Cut, and the West. The causeway is an important lifeline, providing access to state and county parks, the village of Key Biscayne, the Miami Seaquarium, the University of Miami’s Rosenstiel School of Marine and Atmospheric Science, and, perhaps most significant of all for those working on the project, the Crandon Park Tennis Center. The center is home to the Sony Open, which is scheduled to begin March 17, 2014, a deadline that keeps Kiewit project manager Frank DiGilio up at night. The clock on the 300-day construction schedule began ticking on May 1.
Of the three bridges, the Bear Cut and the West are being overhauled. “It’s a very aggressive schedule, and we go up from there,” says DiGilio. “We’re right on the ocean with Bear Cut and susceptible to hurricanes and Atlantic storms. One misstep in obtaining permits or interference by Mother Nature can turn the very aggressive schedule into a nightmare.”
Kiewit hired New York City–based Hardesty & Hanover, LLP, to handle the design work on the design/build project, and the latter subcontracted with Calvin, Giordano & Associates, Inc., of Fort Lauderdale, Florida, for drainage, lighting, surveying, and roadway signs and striping. Eisman & Russo, of Jacksonville, Florida, is performing the construction engineering and inspection. The lump-sum project is budgeted at $31 million, the bulk of the funding coming from county bonds backed by an increase in tolls on the causeway.
The original bridges comprised concrete substructures, steel girders, and concrete decks. In the early 1980s the bridges were widened with concrete substructures, prestressed-concrete girders, and concrete decking. Repairs have been made over the years, and last year the Florida Department of Transportation found deterioration in the steel beams on both bridges, resulting in traffic realignments and lane restrictions.
Marcos Redondo, the head of bridge engineering in the causeways division of Miami-Dade County’s Public Works and Waste Management Department, says that the project will involve the complete removal and replacement of the beams and the deck and will address any substructure deficiencies in the process. The Bear Cut Bridge is also being widened by 20 ft in order to accommodate 14 ft wide pathways on either side. “This will provide great safety to the tremendous bicycle traffic out there as well as pedestrians,” says Redondo. “They will be separated by a concrete barrier.”
View a larger version of the elevation of the completed
structure. Miami-Dade County Public Works & Waste Management
As part of the work, the 12 in. diameter water main, which is attached to the spans, will be replaced by 16 in. diameter high-density polyethylene (HDPE) pipelines running beneath Biscayne Bay. The new lines will be installed under a separate contract by means of horizontal directional drilling. Hazen and Sawyer, of New York City, is handling the design.
DiGilio says the staging of the rehabilitation project had to be considered carefully. “The difficulty with this project lies in the requirement that we keep four lanes of motor vehicle traffic going, plus the pedestrian traffic,” he says, adding that this means the work will have to be done in phases. For instance, on Bear Cut, which at 2,100 ft is by far the longer of the two spans undergoing repair, crews will demolish and reconstruct the northern part of the bridge while maintaining traffic on the southern half. In the next phase they will divide the traffic and demolish and reconstruct the center portion of the bridge. The southern portion was rebuilt in 1983, “and nothing will be done with that,” says DiGilio.
Crews are working night and day six days a week. Tim Noles, P.E., M.ASCE, the principal in charge of the project for Hardesty & Hanover, says that to fast-track the construction the designers specified precast-concrete panels for the concrete deck forms and a modified version of the beam typically called for in the guidelines issued by the American Association of State Highway and Transportation Officials. “It’s a custom beam for this particular structure depth,” Noles says.
Jenna Martinetti, the project manager for Calvin, Giordano & Associates, says that drainage challenges will also have to be addressed. “We’re over Biscayne Bay, which presents its own drainage issues,” she explains. “Because there are existing approvals by regulatory agencies, we’re able to retain the existing drainage flow, but we have to do extra treatment for the widened roadway.” Kiewit is coordinating the design work with Hardesty & Hanover to make the plans as “construction friendly as possible,” says DiGilio.
Given the potential for high winds and heavy waves, careful attention has been given to the substructure supports below the waterline. “We had two dives to the understructure of the bridges,” says Redondo. As a result, 84 new piles are being installed beneath the Bear Cut Bridge to provide additional lateral support.
The project has been somewhat controversial; the Village of Key Biscayne wanted a complete replacement of the Bear Cut Bridge. But Redondo says that the county has done its due diligence in determining that repair and rehabilitation constituted the best and most cost-effective course of action. “Over 50 percent of the bridges are being replaced in a very short time,” Redondo says.