Loess landslides are one of the most important natural hazards among various landslide types in China, and rainfall is the main factor triggering loess slope instability. To gain deeper insights into the processes behind slope failure triggered by precipitation, this study conducted an indoor slope rainfall modelling test based on the case of the Shixiakou landslide in Jinzhou, Lanzhou. The test employed a custom-built rainfall simulation device, precisely controlling rainfall intensity and duration to mimic natural rainfall conditions. Soil moisture sensors, pore-water pressure transducers, and strain gauges were strategically installed within the loess slope model to monitor soil moisture dynamics, pore-water pressure variations, and lateral stress distribution in real-time. This investigation examined the progressive failure mechanism of loess slopes under rainfall infiltration through integrated monitoring. The experimental results demonstrate that sustained precipitation triggers a sequential failure process characterized by four distinct phases: initial surface scouring, subsequent basal slope instability, progressive mid-slope shear failure, and ultimate crown section collapse, and finally traction failure mode. It is worth noting that cracks play a crucial role in slope failure by creating preferential channels for water infiltration and subsequent failure development.
Li et al. (Fri,) studied this question.