Coupled Infiltration and Kinematic-Wave Runoff Simulation in Slopes: Implications for Slope Stability

Shallow translational slides are common in slopes during heavy rainfall. The classic model for the occurrence of translational slides in long slopes assumes rising saturation above a slip surface that reduces the frictional strength by decreasing the effective stress along soil discontinuities. The classic model for translational slope failure does not conform well to the nature of homogenous soils that do not exhibit discontinuities propitious to create perched groundwater over the soil discontinuity or slip surface. This paper develops an alternative methodology for the coupled numerical simulation of runoff and infiltration caused by variable rainfall falling on a slope. The advancing depth of infiltration is shown to affect the translational stability of long slopes subjected to rainfall, without assuming the perching of soil water over the slip surface. This new model offers an alternative mechanism for the translational stability of slopes that are saturated from the slope surface downwards. A computational example illustrates this paper’s methodology.