Research on the Safety Factor Model of Frozen Soil Slopes During Thaw Collapse Considering Temperature Effects

With the global climate warming, the temperature conditions in permafrost regions have changed significantly, and the stability of permafrost slopes is facing serious threats. This paper focuses on the construction of the instability mechanism and prediction model of permafrost slopes considering the influence of temperature. By analyzing the thermokarst collapse process of permafrost slopes, the characteristics and causes of stages such as the soil loosening period and the surface sloughing period were studied. Based on the Mohr–Coulomb strength criterion, combined with the simplified Bishop method and the Morgenstern–Price method, a mechanical analysis of the critical state was carried out, and a safety factor formula applicable to the critical state of permafrost slopes was derived. From the curves of the total cohesion and effective internal friction angle of the experimental soil changing with temperature, an influence model of temperature on the strength parameters was fitted. Considering the factor of freeze–thaw cycles, a safety factor model for permafrost slopes was constructed. Through a large amount of data calculation and analysis of the model, the reliability of the model was verified. This model can be used to predict slope states in practical assessments and optimize slope support structure design parameters in cold regions, providing important references for ensuring engineering safety, reducing geological disasters, and promoting sustainability in cold regions. Finally, potential mitigation measures for frozen soil slope instability based on the findings are briefly discussed.