Nonlinear seismic response and parametric examination of horizontally curved steel bridges using 3D computational models

The seismic behavior of horizontally curved steel bridges is more complex than straight bridges because of their curvature and other parameters. Studies that attempt to develop methods to efficiently predict their seismic response have been somewhat limited to date. A computational modeling approach was examined to assist with understanding the seismic behavior of these bridges. The computational, three-dimensional (3D) bridge models consisting of the concrete deck, steel girders, cross-frames, pier columns and caps, and abutments and footings were created in OpenSees and examined for accuracy via application to a representative, three-span continuous curved steel plate girder bridge in Pennsylvania. Sensitivity studies in the form of tornado analyses were also carried out to investigate the influence of critical curved bridge parameters on the seismic response using a group of representative bridges. Each representative bridge was subjected to an ensemble of synthetic ground motions, and seismic response was examined. Results from the sensitivity study indicated a 17-22% variation in maximum bearing and abutment deformations, column curvature ductility, and cross-frame axial forces parameters for the range of bridge radii and span numbers that were investigated.