Abstract: In this research, we simulate the dynamic response characters and failure mechanism of landslide by using the universal distinct element code(UDEC). Enziping landslide No. 2 in the Xiluodu reservoir area of Jinsha river is taken as example, and Ninghe-Tianjin earthquake record as the dynamic parameter. Simulated results show that: 1) under earthquake action, slope shows obvious amplification effect, and amplification effect of acceleration is the biggest, followed by displacement, velocity; 2) area of shear stress concentration and the shear strain of the slip zone dramatically increase after the peak value of the seismic wave, and the deformation and failure extended from the front to the rear of the slip zone due to the accumulation effect of shear strain; 3) safety factor of landslide stability is less than 1.0 and the maximum accumulated displacement is up to 1.58 m when the earthquake stops. Through analyzing calculated data, we conclude that failure mechanism of the landslide results from the combination effect of motion amplification and shear stress concentration and the accumulation of shear strain, and the failure mode remains bedding slide. In light of failure state of the landslide, we give suitable anchoring treatment suggestions for reducing the risk of river closure by earthquake-induced landslide so as to ensure the operation of Xiluodu hydropower project.

Key words: bedding landslide, earthquake, dynamic response, deformation and failure mechanism, discrete element method