## 2 Preparation
### Determination of Macro Parameters
Under a confining pressure of 300 kPa, the difference in peak stress is more minor and even occurs when the peak stress of 10 freeze-thaw cycles exceeds 5 freeze-thaw cycles. The reason is that in addition to the slight gap between the samples, the freezing and thawing process and the effect of confining pressure will change the internal porosity and cementation degree of the soil-rock mixture, which will have a particular impact on the strength of the SRM sample. Under the action of high confining pressure, the effect of transverse confining pressure compensates to a certain extent for the damage experienced by the specimen during the freeze-thaw cycle. As a result, the peak stress gap under 300 kPa confining pressure is smaller than that under 100 kPa. * The effect of the number of freeze-thaw cycles on the peak stress of soil-rock mixture: Based on the data obtained from the triaxial test of the soil-stone mixture specimen subjected to freeze-thaw cycles as well as the stress-strain curve, the triaxial compressive strength of the specimen at 10% strain can be determined, and the data corresponding to each level of peripheral pressure and the number of freeze-thaw cycles are shown in Table 1.  
It can be seen from the curve that when the number of freeze-thaw cycles increases from 0 to 10, the peak stress decreases by 65 kPa at a confining pressure of 100 kPa. The peak \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Number of Freeze–Thaw Cycles (Times)** & \multicolumn{3}{c}{**Compressive Strength (kPa)**} \\ \hline  & **100 kPa Perimeter Pressure** & **200 kPa Perimeter Pressure** & **300 kPa Perimeter Pressure** \\ \cline{2-4}
0 & 345.65 & 554.63 & 735.60 \\
1 & 325.59 & 523.50 & 724.18 \\
3 & 310.24 & 500.49 & 687.45 \\
5 & 296.75 & 511.27 & 661.69 \\
10 & 280.19 & 476.62 & 666.16 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Compressive strength of soil–rock mixtures under different numbers of freeze–thaw cycles. Figure 5: Stress–strain curve of SRM under different freeze–thaw cycles: (**a**) 100 kPa perimeter pressure; (**b**) 200 kPa perimeter pressure; (**c**) 300 kPa perimeter pressure. stress of the sample decreases as the number of freeze-thaw cycles increases, indicating that the freeze-thaw cycle has a specific damage effect on the soil-rock mixture. The more cycles, the higher the degree of damage. This is because the pore water of the SRM sample condenses into ice during the freezing process, and the volume expands, generating internal stress inside the sample. As a result, the compactness of the sample is reduced, and the pores are enlarged. After melting, the damage caused cannot be recovered, resulting in a reduction in strength; under a confining pressure of 200 kPa, the peak stress is reduced by 78 kPa, and the peak stress appears reversed after freezing and thawing 5 times. This condition continues to decrease after 10 freeze-thaw cycle times; under a confining pressure of 300 kPa, the peak stress decreases by 44 kPa, and the peak stress appears reversed after 10 freeze-thaw cycletimes On one hand, the soil and rock content and distribution during the preparation of the SRM affect its mechanical properties. On the other hand, in the case of high confining pressure, the effect of confining pressure will compensate for the damage caused by freezing and thawing to a certain extent. It can be seen from Figure 6b that under different freeze-thaw cycles, the peak stress of the SRM increases linearly with the increase in confining pressure. The slopes of the curves for different freeze-thaw cycles are almost the same, indicating that the freeze-thaw cycle does not affect the sensitivity of the SRM samples to confining pressure.