Seismic response of a cable-stayed bridge deck under multi-component non-stationary random ground motion

A Markov method of analysis is presented for obtaining the seismic response of cable-stayed bridges to non-stationary random ground motion. A uniformly modulated non-stationary model of the random ground motion is assumed which is specified by the evolutionary r.m.s. ground acceleration. Both vertical and horizontal components of the motion are considered to act simultaneously at the bridge supports. The analysis duly takes into account the angle of incidence of the earthquake, the spatial correlation of ground motion and the quasi-static excitation. A cable-stayed bridge is analysed under a set of parametric variations in order to study the non-stationary response of the bridge. The results of the numerical study indicate that (i) frequency domain spectral analysis with peak r.m.s. acceleration as input could provide more r.m.s. response than the peak r.m.s. response obtained by the non-stationary analysis; (ii) the longitudinal component of the ground motion significantly influences the vertical vibration of the bridge; and (iii) the angle of incidence of the earthquake has considerable influence on the deck response. Copyright (C) 2003 John Wiley Sons, Ltd.