FORMATION MECHANISM AND INSTABILITY MODEL OF KAPO SOIL COLLAPSE GROUP IN WENSU COUNTY, XINJIANG

Soil collapse is a kind of geological hazard with high risk and widespread distribution. It is also a hot topic in the field of geological hazard research. In recent years, the frequency of soil collapse disasters in Aksu Area has increased significantly. Especially the soil collapse group centered in Kapo area of Wensu County is the most typical. Due to the influence of topography, complex strata and erosion, there are still many hidden points of the collapse in this area, seriously threatening the life and property safety of surrounding residents. Based on field investigation, data collection, theoretical analysis and remote sensing image analysis, this study discusses the basic characteristics and types of geological hazards of the Kapo collapse group in Wensu County, deeply analyzes its influencing factors and formation mechanism, and summarizes the process of the instability model. According to the evolutionary relationship of the collapse and instability process, the initiation law and evolution model of the disasters are summarized. The results show that the formation of Kapo collapse group is the result of coupling of multiple factors, especially the soil properties and rainfall. In addition, the collapse in the study area is mainly in toppling mode. Aiming at the kinematic instability mode of this type, this paper starts from multiple perspectives, such as joint fracture development, rainfall infiltration, slope cavity failure and soil strength change. The instability evolution process of toppling collapse can be summarized into four processes: Strip fissure-concave cavity development stage, the action stage of water-joint plane, the toppling movement stage of dangerous rock mass along the support point, and the unstable accumulation stage of collapse body. The research results of this paper can provide reference and theoretical support for the systematic study of the formation mechanism and instability law of similar soil collapse.