STUDY ON EVOLUTION CHARACTERISTICS OF XIANGPINGSHAN LANDSLIDE BASED ON PARTICLE DISCRETE ELEMENT METHOD

The safe operation of Wenshan-Malipo Expressway is seriously affected by the Xiangpingshan landslide. In this paper,the genetic mechanism,evolution characteristics,potential stability and treatment measures of Xiangpingshan landslide are studied by conducting geological survey,numerical simulation and field monitoring. The numerical simulation results are consistent with the deformation and failure features in the field. The research results show that: (1)Xiangpingshan landslide is a medium-scale traction landslide composed of rock-soil mixtures,the muddy weak layer is formed in the slope as a potential slip zone due to the long-term action of groundwater at pre-topping failure part of rock mass,and slope deformation and failure are finally caused by the excavation at the slope toe; (2)In the longitudinal direction,the deformation rates of the middle and rear parts of the sliding body show slight variation since the muddy weak zone becomes a unified sliding zone,but the deformation rates at the leading edge vary with different free conditions,and the deformation features vary greatly in the transverse direction with topographic changes; (3)A new sliding surface is gradually forming after long-term evolution of the sliding body and causes the failure from the top of the anti-slide pile,threating the safe of the expressway; (4)Two rows of anti-slide piles and water interception-drainage measures are effective and reliable in the treatment of Xiangpingshan landslide.