Causal Analysis and Stability Evaluation of Loess Landslide in Yili Region of Xinjiang - A Case Study of Alar Village Landslide

Loess landslides are pervasive in the Yili region of Xinjiang province. Loess landslides occur with some inherent conditions and external triggers. Taking the Alar Village landslide in Yili as an example, first, detailed investigation of the inherent conditions of landslides were investigated, such as slope lithologies, geological and hydrogeological conditions. Then, physical and mechanical properties of the landslide materials are measured in laboratory. Experiment results showed that rainfall has a great influence on the physical and mechanical parameters of loess. Under natural conditions, the internal friction angle of loess is 24.5° and the cohesion is 28.4 kPa, while under saturated condition, the mechanical parameters of loess decreased sharply, and the internal friction angle is 16.5°, cohesion of 11.0 kPa. Combined with external triggering factors such as rainfall and earthquake, landslide stability is evaluated by two-dimensional limit equilibrium and finite element method. The simulation results indicated that the factor of safety of slope is the lowest under the earthquake condition. With the groundwater level gradually increased, the factor of safety of slope gradually decreased. The research results can provide theoretical guidance for landslide prevention and control in Yili loess area.