Slope unit-based approach for assessing regional seismic landslide displacement for deep and shallow failure

Abstract

Grid-based approach is typically adopted to estimate the Newmark-type displacement for regional seismic landslide hazard assessment. However, the approach is limited to the assumption of infinite slope and rigid block movement, which may be different from the actual behavior of slope under seismic loading. In this study, a slope unit-based approach is proposed to quickly estimate earthquake-induced displacements for finite slopes in regional scale. Hence, regional seismic landslide hazard can be assessed by the estimated displacements. The approach is advantageous as it considers slope geometry, determines the failure mode automatically, and considers the interaction of incident wave and slope. The implementation of the approach is demonstrated by considering two areas that experience severe landslides during the Chi-Chi and Northridge earthquakes. Results show that the prediction rate of the proposed method is up to 73% compared with the landslide inventory given the estimated displacements.