A Deep Catastrophic Failure Model of Hillslope for Numerical Manifold Method and Multiple Physics Computation

Abstract

This study was aimed to create an analytical model for simulating deep catastrophic failure of hillslope (or deep-seated landslide) to help determining assessment criteria of potential risk based on numerical manifold method (NMM) and coupled multi-physics computation (MPC), in which the failure status is simulated by the NMM while the risk factors are studied by the MPC. The simulation delivers the landslide results that are compared with a laboratory test for approval. The proposed model includes a small-scale hillslope designed by two-dimensional geometry for the plane strain problem. Thus, the porous materials are considered for coupling fluid–structure interactions in hydraulic and geotechnical analyses. Meanwhile, discontinuous joints are assumed along the potential failure surfaces within the deep-seated layer to simulate collapse behaviors of hillslope once the risk factors, such as effective stress and friction angle, reach the thresholds. Furthermore, the model is initially setup as laboratory scale for comparing with a hydraulic experiment that practices the failure condition caused by seepage. The simulation hence explorers the criteria of potential failure risks due to variations of slope, friction angle, and groundwater level. This study performs feasibility of the proposed model that provides a reliable procedure based on both simulation and experiment to estimate the potential risks for deep catastrophic landslides. In the future, the study can be expanded for evaluating full-scale landslide in a variety of hillslope properties.