Slope Failure Analysis using Semi-Implicit MPM for Unsaturated Soil

Abstract

We develop a semi-implicit MPM to properly express the mechanical behavior of unsaturated soil based on Biot's mixture theory. The fractional-step method is incorporated into the MPM to implicitly solve the pore water pressure and evaluate the interaction force due to the viscosity using the intermediate velocity field. Thanks to these features, both the numerical stability and computational efficiency are improved. Several numerical examples are presented to demonstrate the capability and performance of the proposed method. In particular, a validation analysis is carried out using a model experiment of infiltration-induced slope failure.