Abstract: An ancient landslide in Shangnan is studied in this paper. A twodimensional numerical model is established by using the discrete element method. The data of displacement, vector, monitoring point and measurement circle at different time are compared and analyzed. The results show that the strength of landslide rubble deposit and gravel layer is low, and the landslide slope is steep. The rubble deposit first slides from the toe of the slope, and the rear particles also slide downward to a certain extent due to the loss of the support of the front particles, so the entire rubble deposit slides. The gravel layer also partially slides under the drive of the gravel accumulation layer due to its low strength. The sliding zone appears at the interface between the gravel accumulation layer and the gravel layer, while the other three layers do not slide due to their high strength. Based on the above analysis, it is suggested that support measures should be taken for landslide to ensure the safety of engineering construction.

Key words: Landslide, Discrete Element, Overall Sliding