The aim of this research is to understand and quantify the modeling differences between CSiBridge and OpenSees, and to determine sensitive model parameters. When designing bridges for the high seismic region of California, the California Department of Transportation (Caltrans) performs nonlinear time history analysis of their bridge models. For three-dimensional models, the bridge response generated from CSiBridge/SAP2000 differs from the bridge response generated from OpenSees. For this research, Caltrans provided four Ordinary Standard Bridge designs and their corresponding three-dimensional CSiBridge input files. These files, along with three-dimensional models created in OpenSees, are employed to understand the differences in modeling assumptions between the two software packages.
To validate OpenSees as a modeling tool, mode shapes and pushover results in OpenSees were compared to CSiBridge results. Next, to validate OpenSees in sensitivity analysis, elastic materials were used to model the bridge structure. Next, a sensitivity analysis is performed in OpenSees, and sensitive input parameters are identified. Future work includes the implementation of nonlinear material properties and modeling recommendations.