###### Abstract
[14] examined fracture evolution, energy dissipation, and damage characteristics in sandstone and marble post\(-\)freeze-thaw cycles, highlighting the significant impact of initial freeze-thaw treatments on rock fracturing. To date, in situ testing of freeze-thawed rock mass mechanical properties remains unreported. However, scholars have indirectly estimated freeze-thaw impacts using rock mass quality evaluations or the Hoek-Brown criterion based on laboratory tests and field surveys of weathering. [PERSON] et al. [15] determined the degradation of RMR values and rock mass quality at the Yulong Copper Mine slope in Tibet under freeze-thaw cycles by integrating fracture spacing, condition, and RQD data. [PERSON] et al. [16] proposed the TSMR system for slope rock mass quality assessment in the Tianshan Highway area, incorporating freeze-thaw coefficients derived from experiments, rock hardness, and field investigations into the RMR, SMR, and CSMR frameworks. [PERSON] et al. [17] quantified freeze-thaw disturbance factors and GSI values using ultrasonic wave velocities of freeze-thawed samples, enabling the estimation of slope rock mass mechanical parameters via the Hoek-Brown criterion. Their work revealed exponential decay patterns in uniaxial compressive strength and the elastic modulus. [PERSON] [18] developed a freeze-thaw damage strength criterion by modifying Hoek-Brown parameters to account for degradation, enabling the quantification of strength parameter deterioration with freeze-thaw cycles. In [PERSON] et al. 's research [19], the maximum safe slope angle of fractured rock masses was optimized by eliminating slope angles inducing unstable blocks (key blocks) and by using the stereographic projection method of the key block theory. [PERSON] et al. [20] numerically modelled pit wall stability using finite element analysis, optimizing boundaries for complete ore excavation, and identified safety factor distribution, potential sliding surfaces, and the influence of wall slope and ore completeness on the stripping ratio in a super\(-\)deep open pit. Traditional indoor freeze-thaw tests typically use temperature settings based on ambient air conditions, which effectively capture the response of shallow rock masses. However, as burial depth increases, significant discrepancies arise between rock mass temperatures and atmospheric fluctuations. These standardized temperature protocols fail to simulate true freeze-thaw responses in deep rock masses, compromising the accuracy of slope stability evaluations and physical-mechanical parameter estimations. To address these limitations, this study focuses on the Wushan Open\(-\)Pit Mine in a typical cold region. We analyze the correlation between extreme rock temperatures and burial depth, conduct freeze-thaw experiments across varying temperature ranges, and assess the evolution of mechanical properties and slope stability under freeze-thaw conditions. Technical Approach for Strength Degradation and Stability Evaluation of Slope Rock Mass Under Freeze-Thaw Cycles  
The technical roadmap for characterizing mechanical parameters and evaluating the stability of slope rock mass under freeze-thaw cycles is shown in Figure 1. First, based on the actual extreme temperature values within the slope over one year, the freeze-thaw cycle test temperatures were set. Through conducting freeze-thaw cycle experiments, the attenuation patterns of the uniaxial compressive strength and tensile strength of rocks under different numbers of freeze-thaw cycles and burial depths were obtained. Subsequently, the \(m_{i}\) value (rock hardness/softness index) was calculated based on experimental results. Coupled with the Geological Strength Index (GSI) and the generalized Hoek-Brown strength criterion, the cohesion and internal friction angle of the rock mass were determined.