Validation of Fault Rupture-Response Spectrum Analysis Method for Curved Bridges Crossing Strike-Slip Fault Rupture Zones

Abstract

In response to the bridge damages observed in past earthquakes and the absence of practical analysis methods, a simplified analysis procedure named the fault rupture-response spectrum analysis (FR-RSA) method was developed in this research as an alternative to the onerous nonlinear response history analysis (RHA) method for bridges crossing strike-slip earthquake fault rupture zones. For validation of the FR-RSA method, this research investigated seismic responses of two representative curved bridges in California, including one three-span bridge and one four-span bridge. The selected bridges were analyzed using both the FR-RSA method and the nonlinear RHA method. Ground motion, earthquake fault rupture location, and fault orientation 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.