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/622975
PROJECT SR 417 and Boggy Creek Road Interchange Florida’s first curved precast concrete U-girder bridge by Thomas W. Stelmack, Thomas E. Davidson, and Kristian Forars, Parsons Orlando International Airport (OIA) has become the fourth busiest domestic destination in the United States due to Orlando, Florida’s, many tourist attractions, job opportunities, and climate. With the steady increase in travelers, the interchange for the south entrance to the airport has become more congested. For many years, planners with the Central Florida Expressway Authority (CFX) have known the need for improving the movements from State Route (SR) 417, part of CFX’s tollway around Orlando, to Boggy Creek Road and the south access road to OIA. The third and final phase of the interchange includes two direct flyover movements: • Ramp H carries drivers from northbound SR 417 over Boggy Creek Road and SR 417 to the south access road of OIA • Ramp I provides the opposite movement, carrying drivers over Boggy Creek Road and SR 417 from the south access road of OIA The horizontally curved superstructures for Ramps H and I were originally designed with both steel trapezoidal box girders and precast concrete curved U-girder alternates. The design for the U-girder alternate used PCI Zone 6 concept plans adopted by the Florida Department of Transportation (FDOT) and was completed in less than 12 months. Bids for the precast concrete curved U-girders were ultimately accepted in October 2013, with the low bid of $71 million ($33.78 million for the two ramp structures) estimated to be a savings of $7 to $9 million over a steel design. Design Details Geometry The project has two flyover ramps that were designed using curved precast concrete U-girders. Ramp H is approximately 55 ft above ground surface at its highest point and consists of three continuous units for a total length of 2708 ft. Each unit is comprised of several spans ranging in length from 141 to 216 ft. Ramp H has a minimum horizontal radius of 1273 ft and the width of the bridge deck is 45 ft 3½ in. with two travel lanes. Ramp I crosses over Ramp H, rising 90 ft above ground surface at its highest point and has two continuous units with a total length of 1411 ft. It has spans ranging in length from 177 to 220 ft, with a minimum horizontal radius of 955 ft, a bridge deck width of 36 ft 3½ in., and one travel lane. PROFILE SR 417 AND BOGGY CREEK ROAD INTERCHANGE / ORLANDO, FLORIDA BRIDGE DESIGN ENGINEER: Parsons, Denver, Colo. and Orlando, Fla. PRIME CONSULTANT: Dewberry, Orlando, Fla. INDEPENDENT CHECK ENGINEER: URS Inc., Tampa, Fla. CONSTRUCTION ENGINEER: Summit Engineering Group, Littleton, Colo. CONSTRUCTION INSPECTION: A2 Group Inc., Orlando, Fla. POST-TENSIONING INSPECTION: FIGG, Tallahassee, Fla. PRIME CONTRACTOR: SEMA Construction, Orlando, Fla.