Soil–rock mixture slope stability analysis by microtremor survey and discrete element method

Soil–rock mixtures (S-RM) are widely distributed in mountainous regions worldwide. Because of their complex material composition and special physical and mechanical properties, S-RM are an important carrier of many landslides and have brought catastrophic consequences to humans. Accurately investigating the structure of an S-RM slope is the fundamental basis for evaluating the mechanism of a landslide, and a good understanding of the landslide slide process is the core content of hazard assessment and disaster reduction. In this study, taking the S-RM landslide in Baidian Township, Hunan Province, as the research object, the microtremor survey method (MSM) was introduced to detect the slope, and the rock block structure and distribution data in the slope were accurately obtained. Then, by means of the discrete element method (PFC2D), the dynamic slide process of the S-RM landslide was analysed. The study results show that the MSM has a good effect on the detection of S-RM. The presence of rock blocks makes the deformation and failure of the slope complex, and the stability coefficient increases. The interaction between the rocks and the friction between the rocks and the bedrock during the sliding process of the slope causes the sliding velocity to clearly fluctuate. The results of this paper could be used as a reference and a basis for landslide disaster prevention and mitigation.