This thesis evaluates the application of a simplified analysis procedure as implemented in version 16 of CSiBridgeTM for design of bridges crossing earthquake fault ruptures. The fault-rupture response spectrum analysis (FR-RSA) approximation method has been proved adequate for both straight and curved ordinary bridges, but lacked a comfortable interface to accommodate the method users. Computers and Structure, Inc. has implemented the FR-RSA procedure into CSiBridgeTM, a user-friendly integrated 3-D bridge design software, as an added seismic design feature. By combining the response of the bridge due to the quasi-static displacement from the fault strike-slip rupture and the pseudo-dynamic displacement from the earthquake response spectrum analysis, a combined seismic demand is approximated using the software. The CSiBridgeTM bridge model creation process and application of FR-RSA as the Caltrans Fault Crossing Seismic Design Request is explained and evaluated in this thesis. In order to validate the implementation of FR-RSA in CSiBridgeTM v.16, the bridge demands for a three span and a four span curved bridge crossing earthquake fault rupture zones from the analytical models developed in Open System for Earthquake Engineering Simulation (OpenSees) and CSiBridgeTM v.16 are compared and discussed. It was found that the displacement demands from the abutments and bents were comparable from the two programs, supporting the correct application of the approximation method. This thesis also presents recommendations for improving the analysis function of CSiBridgeTM v.16 for bridges crossing fault ruptures.