## 6 Conclusions  
In this paper, uniaxial compression tests and conventional triaxial tests of rocks under different freeze-thaw cycles were carried out, and the influence of freeze-thaw cycles on the mechanical parameters of rock masses was analyzed. The GSI was determined by combining the on-site structural plane investigation and the acoustic wave method. The mechanical parameters of the rock mass were gained based on the Hoek-Brown criterion, and the rationality of the method was verified by combining the indoor triaxial experiments. The results were used in the stability analysis of slopes to study the characteristics of stress and deformation changes under freeze-thaw cycles, as well as the changes in safety  
Figure 13: Displacement change curve of observation points. coefficients. The results were compared and analyzed with on-site monitoring data, leading to the following conclusions:  
1. As the number of freeze-thaw cycles increased, the uniaxial compressive strength, modulus of elasticity, Poisson's ratio, internal friction angle, and cohesion of the three rock types decreased. Compared to the mechanical parameters without considering freeze-thaw effects, the uniaxial compressive strength of the three rock types decreased by 29.7-45.8%, the modulus of elasticity decreased by 42.7-63.3%, the Poisson's ratio decreased by 16.0-42.1%, the cohesion decreased by 71.7-77.1%, the internal friction angle decreased by approximately 52.0%, and the tensile strength decreased by 79.3-83.6%. 2. Through numerical simulation, it was found that the deformation and stress of the slope increase with the number of freeze-thaw cycles. At F-T = 90, the maximum X-direction displacement of the slope increased by 240 mm, and the maximum tensile stress increased by approximately 0.73 MPa. Judging from the six observation points of the numerical simulation, this is similar to the on-site observation results. The safety coefficient of the slope decreases exponentially with the number of freeze-thaw cycles, reaching F\({}_{\text{s}}\) = 1.105 at F-T = 90, indicating that the slope is in an unsafe state. Compared to the safety coefficient without considering freeze-thaw effects, the safety coefficient decreased by 44.5%. Therefore, freeze-thaw cycles can easily lead to slope instability. 3. Both the numerical simulation results and the field monitoring results show that the slope displacements exhibit a \"stepwise\" growth pattern overall. However, there are slight differences between the two results, primarily due to factors such as loading methods, environmental conditions, and assumptions. It should be pointed out that although the reduction in rock mechanical parameters based on the Hoek-Brown strength criterion has high computational efficiency, it may overly simplify the evolution process of anisotropic damage of rock mass under the action of freeze-thaw cycles. In particular, it fails to distinguish the differential damage between the complete rock mass block and the structural plane, and does not reflect the microstructure damage mechanism caused by phase transformation. Furthermore, the accuracy of analyzing slope stability by combining indoor tests and numerical simulations has a certain gap compared with the actual situation. Future research will explore the following aspects to further refine the theoretical framework of freeze-thaw rock mechanics and enhance engineering applicability:  
1. Refining the relationship between freeze-thaw damage mechanisms and Hoek-Brown parameters by establishing a modified Hoek-Brown-F-T empirical formula, thereby achieving synergistic innovation across theory, experimentation, and modeling. 2. Investigating micro- and meso-scale damage in rocks subjected to freeze-thaw cycles to elucidate the progressive deterioration mechanisms at different structural levels. 3. Developing and applying a constitutive model that quantitatively reflects the degree of rock damage induced by freeze-thaw cycling, enabling more accurate stability predictions for engineering applications. 4.