Study on failure mechanisms of rainfall-induced landslides using physical model experiment and numerical analysis

Abstract

Landslides are one of the most prevalent geological disasters in nature and rainfall infiltration is one of the key triggering factors of landslides. In this study, a laboratory flume model experiment was performed to investigate rainfall infiltration processes and failure mechanisms of sand slopes under artificial rainfall of 90 mm/h. The
numerical simulation was then performed to compare the hydraulic responses and failure mechanism of the slope observed in the experiment. The results of the physical slope model demonstrated that water impounding
and a sudden increase in water level at the slope foot causes the local failure near the slope toe, followed by the development of cracking and retrogressive sliding extending up to the slope’s crest. The simulated results of the phreatic level are in good agreement with the experimental results, indicating the numerical proposed is capable of quantitatively well the hydraulic responses of slope upon rainfall. Both physical and numerical model results highlighted a positive correlation between slope failure and the development of the phreatic level within the slope. The results of this study would provide insights into the slope failure process and provide a dependable methodology for devising solutions to reduce the risk of landslides induced by rainfall infiltration.