Stability Analysis of Prestressed Concrete Through Girder Pedestrian Bridge Under Lateral Impact - Phase I

Project summary:

This project addresses a practical form of pedestrian bridge construction known as the Prestressed Concrete Through-Girder Bridge, in which two prestressed concrete bridge girders support a deck on the bottom flanges. This system is easy to construct, economical and durable, but questions have recently been raised regarding the ductility of these girders, and the stability of the assemblage upon vehicle impact. These bridges are non-redundant simple span systems that could collapse upon vehicle impact if either the girders respond in a non-ductile manner or assemblage becomes unstable. This project represents the first year of a multi-year study on the ductility and stability of Prestressed Concrete Through-Girder bridges. The research in the first years comprises analyses of typical girder cross-sections and bridge assemblages. Alternate cross-section details and bridge configurations will be proposed and investigated if girder ductility and bridge stability are found to be inadequate for Prestressed Concrete Through-Girder bridges currently in use. Funding for additional research will be sought from Mn/DOT as the current project is nearing completion. Future research includes experimental verification of girder ductility and bridge stability, as well as post-test analyses to calibrate the computer models for these bridges.