Investigation of rainfall intensity on the slope failure process using GPU-accelerated coupled MPM

Rainfall-induced slope failure is a common geo-hazard, which can cause catastrophic damages to human life and properties. In order to prevent the occurrence of catastrophes, understanding the mechanism of rainfall-induced slope failure and estimating its failure process is of significant importance. This paper presents a solid–fluid coupling material point method (MPM) in simulating the rainfall-induced slope failure process, and meanwhile, the influence of rainfall intensities on the slope failure process is explored. The solid–fluid coupling MPM is enhanced with a cubic B-spline shape function, rainfall infiltration boundary condition and GPU-accelerated framework, so that a computationally efficient and numerically stable simulation can be realized. One-dimensional consolidation, infiltration and two-dimensional slumping block tests are firstly simulated to test the effectiveness and capability of the solid–fluid coupling MPM in simulating large deformation hydro-mechanical problems. Thereafter, an in-door rainfall-induced slope failure experiment is simulated, where a consistent failure pattern is reproduced. Finally, the influence of rainfall intensity on the slope failure process is studied. Deep-seated and shallow surface failures are two major failure patterns corresponding to small and large rainfall intensities, respectively. Further analyses prove that different evolutions of pore pressure fields and seepage channels play important roles in forming the different failure patterns.