About the Event
Each year a large number of concrete bridges in the United States are hit by over-height vehicles or vehicles carrying over-height objects, not only damaging the structure but in many cases causing injuries and even fatalities. The available literature indicates that highway bridges in such collisions are able to redistribute and transfer the locally-applied impact loads to other parts of the bridge. Pedestrian bridges, however, are of lighter construction and do not have the high degree of redundancy exhibited by highway bridges. These characteristics make pedestrian bridges more vulnerable to collapse under lateral impact.
University of Minnesota researchers recently investigated the safety of a different construction approach for pedestrian bridges: prestressed concrete through-girders. The study consisted of an experimental and analytical investigation of the vulnerability of the prestressed concrete through-girder pedestrian bridge construction used in Minnesota. A series of laboratory tests were performed on representative details and subassemblages to determine the stiffness, strength, and ductility characteristics of critical elements of a typical pedestrian bridge system under representative load configurations. The load-deformation characteristics obtained from the laboratory tests of the individual bridge components and connection regions were incorporated into detailed finite element models to assess the bridge system performance under statically applied lateral loads.
Eray Baran, Graduate Research Assistant, Department of Civil Engineering