Abstract: Traditional slope stability analysis methods could not reflect the whole process of progressive failure from crack initiation, sliding, to piling up. In view of this, a combined finite-discrete element method based on gravity increase method (FDEM-GIM) is proposed to study the slope failure of Red Rock Landslide in Yunnan Province of China. Interface elements are introduced into the surface rock mass of the slope model to build the combined finite-discrete slope model and simulate the critical failure state of slope. The safety factor and the sliding surfaces of the slope are acquired, and then are compared with those obtained by rigid body limit equilibrium method. By increasing the gravity continuously, the progressive failure process of the slope is obtained. The results demonstrate that the proposed FDEM-GIM is feasible in slope stability analysis because the safety factor, the position and shape of the most dangerous sliding face obtained by FDEM-GIM are consistent with those by rigid body limit equilibrium method. Moreover, rigid body limit equilibrium is only suitable for the critical instability state of slope as it could not predict the formation of subsequent sliding blocks, while the proposed FDEM-GIM could further simulate the whole process of slope failure.

Key words: slope stability analysis, gravity increase method, whole process of progressive failure, rigid body limit equilibrium method, combined finite-discrete element method