There are few types of research on the occurrence mechanism and deformation characteristics of landslides induced by permafrost degradation. With the aggravation of climate warming, landslides are more and more common in permafrost regions. A slow landslide (the K178 + 530 landslide) in the permafrost region of the Xiao Xing'an Mountains in Northeast China was monitored for a long time. The deformation characteristics and occurrence mechanism of the landslide were studied using eld investigation, on-site drilling, sensor monitoring, laboratory test, Google satellite image, unmanned aerial vehicle (UAV) photogrammetry, high-density electrical method, and ground-penetrating radar. In addition, a hydro-thermal-mechanical coupling model of frozen soil under saturated conditions was established to simulate the deformation process, pore water pressure change, and effective stress distribution of the slope, and the simulation results were veri ed according to the monitored data. The results show that the meltwater recharge caused by permafrost degradation reduced the cohesion and internal friction angle of the soil near the trailing edge of the landslide, thus providing dynamic and mechanical conditions for slope deformation. The melting of the continuous segregation ice in the active layer contributed to the formation of a sliding surface and provided deformation conditions for the start of the landslide. The combination of these two factors nally led to the occurrence of the landslide. According to its deformation mechanism, it can be judged that the landslide is a thrust-type landslide. In addition, the melting of ice lenses in the seasonally frozen layer is the main source of soil strength damage, and the landslide sliding rate reached the maximum when the ice lens melted completely. The K178 + 530 landslide is a typical case of landslides caused by permafrost degradation. This study provides a reference for the identi cation, early warning, and prevention measures of this type of landslide.
