DETERIORATION CHARACTERISTICS OF ILI LOESS PROPERTIES UNDER FREEZE-THAW CYCLES AND THEIR INFLUENCE ON LANDSLIDE STABILITY

As one of the more sensitive climatic regions in northwest China, the Ili region of Xinjiang has more developed geological hazards. The geological hazards are characterized by serious hazards, high degree of danger and rapid disaster formation, which have great impact on social and economic development. In order to strengthen the prevention and control of geological hazards and build a safe production and living environment, this paper takes the loess landslide in Almal Town, Xinyuan County, Ili Region as the research object. It analyses the characteristics of the strength change of the loess in the area under the action of freeze-thaw cycle and the influence on the stability of the landslide using field geological survey, field sampling and indoor test analysis. The results of the study showed that the strength of the landslide soil deteriorated to different degrees as the number of freeze-thaw cycles increased, while the trend of landslide stability was also consistent with the deterioration of soil strength. The analysis suggests that the spatial structure of the loess is damaged to varying degrees by the freeze-thaw cycles, resulting in changes in soil particle gradation and contact type, which causes the soil strength to deteriorate to varying degrees. The overall stability of the landslide is affected by the freeze-thaw action and changes. After three freeze-thaw cycles, the stability of the landslide changes abruptly, after which the landslide is in a long-term creep-slip state. During this process, the deformation and destabilisation area of the loess landslide is mainly concentrated in the shallow layer of the landslide, and the deformation penetration area is limited to the upper frozen area soil layer, which is not easy to occur in the middle and deep layers, and the degree of landslide deformation is relatively light. The research results can provide reference value for the prevention and mitigation of geological disasters in the Ili region of Xinjiang, and provide guidance for the study of geological disasters of loess landslides in similar areas.