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 I-10/SR 303L System Traffic Interchange Arizona uses efficient concrete bridge geometry to ensure cost effectiveness for its largest system traffic interchange by Andrew Baird, AZTEC Engineering Anchoring the south end of Maricopa County, Arizona’s, newest freeway is a multi-directional system traffic interchange linking State Route 303L (SR 303L) with Interstate 10 (I-10). The I-10/SR 303L System Traffic Interchange (System TI) is a five-level interchange with an embedded frontage road system. The five levels consist of SR 303L one level below grade, at-grade embedded frontage roads and local cross roads, I-10 mainline one level above, and two additional levels of system ramps resulting in structures as high as 90 ft above ground. The embedded frontage road system, a unique design in Arizona, not only enhances the operations of the traffic interchange, but increases the overall footprint to yield the largest System TI in Arizona. Summary of Phase I Structures At the project onset, the design team sought to use cast-in-place concrete box-girder bridges where feasible. Twelve of the 14 structures are cast-inplace, post-tensioned box-girder bridges of various widths and lengths as shown in Table 1. Four of the structures are freeway-to-freeway flyover directional ramps: east to-north (EN), south-to-east (SE), west-to-south (WS), and north-towest (NW). At more than 17 spans and 3412 ft, the longest structure is the Ramp EN bridge. It includes six columns that are 90 ft tall and have integral connections to the superstructure. The two bridges at I-10 over Sarival Avenue at the eastern end of the project are American Association of State Highway and Transportation Officials (AASHTO) Type V precast concrete girder bridges. Collectively, all the major structures include more than 16,700 linear ft of drilled shafts ranging from 48 to 120 in. in diameter, more than 13.8 million lb of reinforcing steel and 71,200 yd3 of structural concrete. The post-tensioned structures used (cont. next page) profile I-10/SR 303L SYSTEM TRAFFIC INTERCHANGE / GOODYEAR, ARIZONA BRIDGE DESIGN ENGINEERS: Arizona Department of Transportation Bridge Group, Phoenix, Ariz.; AZTEC Engineering Group Inc., Phoenix, Ariz.; HDR Engineering Inc., Phoenix, Ariz.; and T.Y. Lin International, Tempe, Ariz. PRIME CONTRACTOR: Pulice Construction Inc., Phoenix, Ariz PRECASTER: Royden Precast LLC, Phoenix, Ariz.—a PCI-certified producer. POST-TENSIONING SUPPLIER: Dywidag Systems International USA, Long Beach, Calif.