Parametric Study of the Effect of Slope Geometry, Soil Properties, and Rainfall Characteristics on the Stability and Deformation of Slope Failures

Abstract

Climate change is causing changes in precipitation patterns around the world with some regions experiencing increased rainfall. This increase in rainfall can result in increased instability and landslide risks, especially in those areas with steep slopes and poor soil conditions. For example, the Pacific Northwest has seen an increase in the frequency of landslides in recent years as a result of more intense and frequent rainfall events. In this study, numerical models, developed in SIGMA/W of GeoStudio, were calibrated and validated using the results from a series of experimental models constructed in a Plexiglas container. These experiments were conducted on models with varying slope inclinations, void ratios, and rainfall intensities. The numerical models were then used to study the impact of slope geometry, soil properties, and rainfall characteristics on deformation of real-scale slope failures. In particular, the models were also used to evaluate the seepage velocity of the infiltrating water as well as the deformation affecting the stability of the slope. Seepage velocity was found to increase with an increase in the void ratio and rainfall intensity as well as duration. The time required for the slope to saturate was found to increase with an increase in the void ratio for a constant slope inclination and rainfall intensity. The swell of the slope was found to remain constant with an increase in the rainfall intensity.