Dynamic response of rock slopes to oblique incident SV waves

Abstract

Most dynamic response analyses of rock slopes only consider the vertical incidence of seismic waves. However, obliquely incident waves dominate in near-field seismic areas. This paper presents a new seismic input method that considers near-field oblique incidence based on mechanisms of artificial viscous boundaries and the influence of incident angle on the dynamic response of rock slopes. Three numerical model slopes with different slope angles of 30°, 45° and 60° are excited with the El Centro earthquake record assuming varying incident angles from 0° to 90°. The results show that the incident angle significantly affects the dynamic response of the slopes. The most damaging incident directions are approximately perpendicular to the slope surface, rather than in the vertical direction. The dynamic response of the slopes will be underestimated if only the vertical incidence is considered. The incident angle affects the reflection wave field in the slope and the areas affected by the reflection waves decrease with increasing slope angle. However, the predominant period of the response spectrum of the rock slopes is not sensitive to the incident angle and location. This study unveils the dynamic mechanism of earthquake-induced rock slides, which is of significance for earthquake hazard prevention.