Instrumentation and Modeling of I-35W St. Anthony Falls Bridge

Abstract

The I-35W St. Anthony Falls Bridge was constructed to replace the steel truss bridge that collapsed on August 1, 2007. The design of the replacement bridge featured a smart-bridge system. The smart-bridge concept included instrumentation for long-term monitoring of the structural behavior of the bridge. Truck-load tests were conducted prior to opening the bridge and 26 months later to measure the response of the structure under controlled loading. The measurements were used to validate a FEM model of the bridge constructed to further investigate the behavior of the structure. The correlation between computed and measured results was found to be good. This paper describes the bridge, the instrumentation installed within the bridge, the FEM model, and validation of the model with respect to the truck-load tests. Recommendations are provided for static instrumentation plans of concrete box-girder structures.