A new runway expansion taking off at Ft. Lauderdale-Hollywood International Airport in Florida will soar above U.S. Route 1 and the Florida East Coast Railway Railroad. Part of the $750 million project is a $200 million joint venture between Tutor Perini Corp. and Baker Concrete Construction to design-build two concrete bridges supporting the runway and taxiway.

The bridge deck must be rated to handle a rough landing of a fully loaded 747. “That’s what drove the thickness of all the components,” says Michael Hernandez, P.E., operations manager for Baker Concrete. “The structure uses 3-foot-thick walls everywhere.”

The Tutor Perini Fort Lauderdale-Hollywood Venture had to divert U.S. 1 to construct the mammoth structure, which consists of six parallel tunnels using 90,000 cubic yards of cast-in-place concrete and topped with a 500,000 square-foot runway deck.

The joint venture began placing concrete in summer 2012, with the design process staying just a step ahead of construction. “This is not a project where we could just walk in and build a completed design that engineers spent years on,” says Hernandez. “We’re continuously interfacing with engineers to make sure the construction methods are efficient.” Hernandez had little precedent to follow; the only other comparable runway spanning highway and railroad operations opened in 2006 at Atlanta Hartsfield-Jackson International Airport.

The complex project has many stakeholders, with the airport seeking an economical solution while meeting Federal Aviation Administration, Federal Railroad Administration, Florida Department of Transportation, and local government regulations. “At every point we’re juggling whose requirements govern what we’re doing right now,” says Hernandez.