Fault-Rupture Response Spectrum Analysis of a Four-Span Curved Bridge Crossing Earthquake Fault Rupture Zones

A simplified analysis procedure named Fault Rupture-Response Spectrum Analysis (FR-RSA) method was recently developed as an alternative to the rigorous but onerous nonlinear Response History Analysis (RHA) method for bridges crossing earthquake fault rupture zones. To validate the FR-RSA method, this research investigats seismic response of a representative four-span curved bridge in California. The selected bridge was analyzed using both the FR-RSA method and the nonlinear RHA method for comparison purpose. Ground motions, earthquake fault rupture locations, and fault orientations were varied in the analyses to expand the validation work under a broad range of the parameters. Result comparisons show that the FR-RSA method provides estimates of peak bridge displacement response that are close enough to the “exact” nonlinear RHA results in all considered cases; therefore, it is recommended for future practical application.