Abstract
The main objective of this study is to determine the influence of exterior shear keys, modeled with nonlinear elements, on the bent displacement demands using dynamic analysis to simulate the response of bridges during earthquake loading. The column displacements are the design parameter of interest since bridges are typically designed to meet displacement demands. Therefore, it is important to determine the displacement as accurately as possible, especially for performance-based design. In addition, more accurate displacement demands may lead to increased economy in bridge design. Four bridge geometries were included in this study to investigate the influence of the change in geometry on the displacement response of the columns and bents. A 3D OpenSees model was created for each bridge geometry and analyzed for a suite of ground motion excitations. The results from the nonlinear model are compared with the results from a linear-elastic model using the California Department of Transportation Seismic Design Criteria, which specifies the use of elastic springs with half of the stiffness of adjacent bent for elastic demand analysis.