One-Weekend Job

Abstract

As part of a national initiative sponsored by FHWA under the Highways for LIFE program, the Utah Department of Transportation (DOT) was awarded a $1 million grant to demonstrate the use of proven, innovative technologies for accelerated bridge removal and replacement. This report documents accelerated bridge construction (ABC) techniques used to remove and replace the 4500 South Bridge on State Route 266 over Interstate 215 in Salt Lake City during a weekend. It includes construction details of the bridge superstructure built offsite on temporary abutments and prefabricated and cast-in-place bridge components and substructure built under the existing bridge without interfering with traffic flow. It also discusses use of a self-propelled modular transporter (SPMT) to remove the old bridge and to replace it with a new one. With conventional construction, the impact of this project on the traveling public was estimated at 120 days, but with accelerated construction techniques the impact was reduced to a single weekend for I-215 and 10 days for State Route 266. Using an SPMT and other ABC techniques added about $0.81 million to the initial construction cost of the project. However, a more comprehensive economic analysis including user cost savings shows that the project saved road users about $3.24 million (or about 36% of the total project costs). Because of the success of this project, the Utah DOT has decided to use ABC techniques more routinely in future projects and has set a goal of making ABC standard practice for all bridges by 2010.