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/306162
The Florida Department of Transportation (FDOT) has completed construction of the initial stage of a three-phased approach for replacing the I-95 and I-295 interchange located 1.5 miles south of the Jacksonville International Airport. The purpose of this project is to improve capacity and operations by replacing the existing partial cloverleaf interchange with an all-directional four-level, system-to-system, high-speed interchange. This initial stage included a new segmental concrete box girder flyover bridge that provides for the southbound I-95 to eastbound I-295 movement along with the widening of an existing beam bridge that supports eastbound I-295 over U.S. 17 and the CSX rail line. Three types of superstructures were considered during the initial Bridge Development Report (BDR). However, only steel box girders and segmental concrete box girders were ultimately considered feasible after the preliminary analysis was completed. This constraint was primarily based on estimated construction costs and issues related to constructability. Another deciding factor was aesthetics. The interchange functions as a main access route to the City of Jacksonville. It is the first major feature experienced by most tourists and visitors traveling into Jacksonville from the north, FDOT agreed with city officials that emphasis should be placed on the aesthetic elements of the bridge as the city's northern gateway. Each alternative was compared for aesthetics, constructability, maintenance costs, and construction cost, with consideration of the present value based on life-cycle analysis. The most influential parameter was construction cost. Construction professionals in Florida generally assume concrete superstructures to be the most economical choice. However, this does not hold true in the case of segmental concrete unless there are peripheral factors such as constructability issues or redundancy in the casting of the segments. Geometric Requirements The span arrangement was similar for both superstructure alternatives and was primarily dictated by the existing features of the interchange. The bridge has a maximum span length of 274 ft and the vertical profile was set to satisfy the required minimum vertical clearance of 16 ft 6 in. The new Ramp SE bridge rises above I-95, existing ramps, and I-295 to become the third-level structure in the interchange. The bridge has a horizontal curvature of more than 90 degrees with a radius of 1250 ft. profile I -95/ I-295 (SR R/SR 9A) NORTH ENTRANCE INTERCHANGE–RAMP SE / JACKSONVILLE, FLORIDA BRIDGE DESIGN ENGINEER: Parsons Brinckerhoff, Tampa, Fla. CONSTRUCTION ENGINEER: Corven Engineering Inc., Tallahassee, Fla. CONSTRUCTION ENGINEERING & INSPECTION: RS&H CS, Jacksonville, Fla. PRIME CONTRACTOR: Superior Construction Co., Jacksonville, Fla. POST-TENSIONING CONTRACTOR: Dywidag Systems International-USA Inc., Bolingbrook, Ill. CONCRETE SUPPLIER: Preferred Materials, Jacksonville, Fla. PRECASTER, SqUARE PILES: Standard Concrete Products, Tampa, Fla., a PCI-certified producer by Victor Ryzhikov, Antonio Ledesma, and Bob Szatynski, Parsons Brinckerhoff The I-95/I-295 NorTh INTerchaNge Cost, constructability, and aesthetics determine overpass design The bridge nearing completion. This view was taken looking southbound and shows the bridge crossing over the exit to eastbound I-295. Photo: Ray Stanyard Photographer. 20 | ASPIRE , Winter 2011 Book_Win11.indb 20 1/4/11 2:34 PM