Slope Stability Assessment using Stochastic Rainfall Simulation

Many regions around the world are vulnerable to rainfall-induced landslides and debris flows. A variety of methods, from simple analytical approximations to sophisticated numerical methods, have been proposed over the years for capturing the relevant physics leading to landslide initiation. A key shortcoming of current hazard analysis techniques, however, is that they typically rely on a single historical rainfall record as input to the hydromechanical analysis. Unfortunately, the use of a single record ignores the inherently stochastic nature of the rainfall process. In this work, we employ a Markov chain model to generate many realizations of rainfall time series given a measured historical record. We then use these simulated realizations to drive several hundred finite element simulations of subsurface infiltration and collapse. The resulting slope-stability analysis provides an opportunity to assess the inherent distribution of failure statistics, and provides a much more complete picture of slope behavior.