Simulation of cyclic slow-to-fast landslides based on the coupled creep and frictional slip model

Abstract

Soft rock slopes may undergo long-term cyclic slow-to-fast landslides due to the softening of clay minerals and frictional sliding under hydromechanical disturbance. We proposed a meso/macroscale cyclic slow-to-fast landslide model by coupling creep and frictional sliding model to address the abovementioned problem. The model can reveal the macroscopic catastrophic phenomena caused by the accumulation of mesoscale damage in soft rocks, thus providing a scientific basis for the simulation of cyclic slow-to-fast landslides. For modeling validation, we applied the model to the Spriana soft rock slope, which undergoes long-term instability under periodic groundwater level variation. By adopting the coupled finite element method and distinct element method (FEM-DEM), the model can mimic the stable creep and fast sliding in different phases of matured slow-moving landslides. The difficulties in simulating cyclic accelerated sliding are solved, where the simulation error of displacement is less than 5.7 % compared with field monitoring data. It may serve as a prediction tool for cyclic slow-to-fast landslides.