## 2 Preparation
### Determination of Macro Parameters  
After the SRM sample's consolidation, freezing, and thawing, the unconsolidated, undrained triaxial test sample is shown in Figure 3a. In comparing the samples with different freezing and thawing times when not pressed, the damage caused by the number of freezing and thawing cycles did not appear on the surface of the sample. As shown in the Figure 3a, no major difference was observed in the surface of the samples after 0, 3, and 5 freeze -thaw cycles. Figure 3b shows the shape of the sample that was frozen and thawed 3 times, 5 times, and 10 times after being destroyed under a confining pressure of 100 kPa. Figure 3c  
Figure 3: Comparison of samples before and after the lab test. (**a**) Specimens frozen and thawed at different times. (**b**) Specimens damaged under different peripheral pressures. (**c**) Specimens damaged by different numbers of freezing and thawing. shows the damage of the specimen under the same circumferential pressure for 3, 5 and 10 freeze-thaw times. Comparing the three situations, it can be found that the SRM sample shows a bulging failure form under the action of axial pressure. The increase in freeze-thaw cycles does not have a major impact on the failure form of the soil-rock mixture. The increase in lateral confining pressure restrains the specimen's lateral deformation, so the specimen's lateral deformation under 200 kPa and 300 kPa confining pressure is smaller than that of the specimen under 100 kPa confining pressure. Stress-Strain Curve
* Stress-strain curves of SRM after freeze-thaw cycles under different confining pressures:  
The SRM sample with a moisture content of 21% was subjected to 0, 1, 3, 5, and 10 freeze-thaw cycles. A total of 15 samples were subjected to unconsolidated and undrained triaxial tests. The confining pressures were 100 kPa, 200 kPa, and 300 kPa, respectively, and the obtained stress-strain curves are shown in Figure 4.  
Figure 4, respectively, lists the stress-strain conditions of the SRM under different confining pressures under the condition of constant moisture content. It can be seen from the above figures, Figure 4a-e, that under confining pressure and different freeze-thaw cycles, the change trends of the stress-strain curves of the SRM are similar, showing the phenomenon of \"rapid growth--slow growth--unchanged stress\", which corresponds to the SRM sample test--the process of elastic deformation-hardening yield-sample failure. At the same time, by comparing the sample curves with different confining pressures, it can be found that the higher the confining pressure, the higher the axial stress the sample can withstand, the higher the strength, and the longer the strain hardening process of the  
Figure 4: Stress–strain curve of SRM under different confining pressures. (**a**) At 21% moisture content and 0 freeze–thaw cycles. (**b**) At 21% moisture content and 1 freeze–thaw cycle. (**c**) At 21% moisture content and 3 freeze–thaw cycles. (**d**) At 21% moisture content and 5 freeze–thaw cycles. (**e**) At 21% moisture content and 10 freeze–thaw cycles. sample. Under the confining pressure of 300 kPa, when the strain reaches 10%, the axial stress of the sample continues to grow slowly. * Stress-strain curves of SRM under different freeze-thaw cycles: It can be seen from Figure 5a-c above that under a confining pressure of 100 kPa, as the freeze-thaw cycle increases, the axial stress that the SRM sample can withstand gradually decreases, while under a confining pressure of 200 kPa, the axial stress difference between the number of freeze-thaw cycles is reduced from 1 to 10. At 5 freeze-thaw cycles, the axial stress exceeds that of the sample with 3 freeze-thaw cycles. The reason may be that it is impossible to accurately control the distribution of soil and rocks in each sample during the sample preparation process, and this reason also exists in studies by other researchers.