Effect of a V‐shaped canyon on the seismic response of a bridge under oblique incident SH waves

Abstract

AbstractTo elucidate the effect of canyon topography on dynamic response of a bridge, an analytical model for a simply supported bridge crossing a symmetric or non‐symmetric V‐shaped canyon in an elastic half‐space under SH waves is proposed. An exact solution to the dynamic canyon‐bridge interaction problem is derived using wave function expansion and verified by its comparison with past exact solution for a sole bridge model without a canyon. The wave propagation in the half‐space, wave scattering by the canyon and wave radiation from the bridge are all taken into account rigorously. Through a systematical parametrical study, it is found that the seismic response of the bridge beam and the wave‐facing side foundation will be significantly amplified. The degree of the topographic amplification is closely related to the geometry of the canyon, the mass and the stiffness of the bridge beam, and the frequency content and angle of the incident wave. The potential adverse effects of a V‐shaped canyon on a bridge should be considered in its seismic design.