Instability of a Rainfall-Induced Landslide Driven by Pore Pressure Generation in the Basal Shear Zone

Intensive rainfall events can lead to the accumulation of pore water pressure within clay-rich shear zones. Under undrained conditions, the reduced effective stress of shear-zone soil ultimately promotes slope failure. This study investigates rainfall-induced landslide initiation through both experimental and numerical approaches. A series of direct shear tests were performed on shear-zone soils to study their response to stress and pore pressure changes under a constant shear stress path. To simulate the initiation mechanism of the rainfall-induced landslide, a hypoplastic constitutive model for overconsolidated clays was employed. The simulation results reveal distinct failure patterns under varying rainfall scenarios, highlighting the critical role of pore pressure dynamics in controlling landslide stability.