Large-deformation modelling of earthquake-triggered landslides considering non-uniform soils with a stratigraphic dip

Abstract

Natural soil slopes often exhibit both spatial variability and stratigraphic dips due to complex depositional processes of soil, exerting a remarkable influence on landslide behaviors. Existing research mostly focused on the influence of soil spatial variability on slope stability or landslide runout behaviors, and the investigation of the effect of stratigraphic dip on large-deformation landslide consequences are relatively limited and have not been fully understood. This study therefore proposed a random large-deformation finite-element (LDFE) computation framework, combining the coupled Eulerian-Lagrangian technique and a three-dimensional (3D) rotational random field to insight the earthquake-triggered landslide consequences considering non-uniform soils with a stratigraphic dip. The whole runout process of earthquake-triggered landslides from activation to termination is realistically reproduced. By implementing both two-dimension (2D) and 3D random LDFE analyses coupled with Monte-Carlo simulations, both effects of spatial non-uniformity and stratigraphic dip of soil on the evolution process and consequences of landslides are analyzed in detail. The results reveal that the stratigraphic dip greatly influences landslide behaviors. In addition, the 2D analyses probably underestimate the landslide consequences when contrasting with 3D analyses. These findings highlight the importance of considering stratigraphic dip of soil slope and the advantage of 3D random LDFE analysis on landslide behaviors.