On a Possible Role of Rayleigh Surface Waves in Dynamic Slope Failures

Abstract

This contribution addresses the effect of a surface wave on the dynamic behavior of a slope. In particular, the interaction of a Rayleigh surface wave, possibly generated by an earthquake or nearby blasting, with a simple wedge-shaped slope is considered. A two-dimensional elastodynamic analysis suggests that the amplitudes and phase shifts of the surface waves reflected and transmitted at the crest strongly depends on the inclination of the slope face, and the superimposition of the reflected and incident waves may induce large stress amplification and thus produce open cracks in the top surface of the slope. The computational semianalytical results are used to investigate the generation mechanism of slope failure caused in the city of Sendai dynamically by the 1978 Miyagi-ken-oki, Japan, earthquake. Finally, the significance of the effect of Rayleigh wave propagation on dynamic slope stability is discussed in comparison with the influence of body waves.