Slope stability analysis model for the frost-susceptible soil based on thermal-hydro-mechanical coupling

Slope stability analysis has been performed through various analysis methods ranging from general limit equilibrium methods, such as those proposed by Janbu, Bishop, and Fellenius, to finite element methods. Using these methods, analyzing the slope stability considering the change in soil stiffness due to the freezing or thawing conditions resulting from temperature changes is infeasible. Therefore, considering this shortcoming, a thermalhydro-mechanical slope stability analysis model (THM-SSA model) is proposed for slope stability analysis. The main feature considered in the THM-SSA model was the slope of the critical state line based on the load angle. Additionally, this model could calculate the local factor of safety (LFS) for the slope based on the isotropic tensile strength of the unfrozen soil and the changes in it after being subjected to repeated freeze-thaw cycles. To verify the proposed THM-SSA model, the stress-strain results were compared with those of the experimental triaxial compression tests that were conducted under different temperatures of the frozen soil with a corresponding number of freeze-thaw cycles. Based on this, a simulation of slope stability analysis was performed as demonstration, and using the verified THM-SSA model, the LFS was calculated according to the freeze-thaw cycles of the slope.