## 5 Conclusions  
In this paper, for the stability of an open-pit mine dump field in a cold area, the mechanical properties of a soil-stone mixture under different numbers of freeze-thaw cycles were investigated using a lab triaxial test and a numerical simulation of the particle flow program. The destructive properties of the soil-stone mixture were investigated from the macroscale and fine viewpoints, and the model of the open-pit mine dump field was  
Figure 23: The relationship between the stability coefficient of the 10 m step slope and the number of freeze–thaw cycles. (**a**) Relationship between maximum particle displacement and folding coefficient. (**b**) Stability coefficient versus the number of freeze–thaw cycles. Figure 24: The relationship between the stability coefficient of the 10 m step slope and the number of freeze–thaw cycles. (**a**) Relationship between maximum particle displacement and folding coefficient. (**b**) Stability coefficient versus the number of freeze–thaw cycles. set up to study the stability law of the slope of the dump field under the conditions of freeze-thaw cycles in terms of the actual dimensions. Thus, the following conclusions were obtained:  
* The stress-strain curves of soil-rock mixtures, tested under triaxial tests of different numbers of freezing and thawing cycles and different water contents, demonstrate similar trends. These curves show three stages: linear growth, stress yielding, and a stage that was unchanged. Additionally, at higher peripheral pressures, the strain hardening phenomenon is more obvious. Comparing the strength changes in a soil-stone mixture under different numbers of freeze-thaw cycles, its compressive strength under 100 kPa peripheral pressure decreases by 65 kPa as a quadratic function of the increase in the number of freeze-thaw cycles, cohesion decreases by 12 kPa, and the angle of internal friction decreases by 2.7\({}^{\circ}\) as a power function of the increase in the number of freeze-thaw cycles. Comparing the stress-strain curves of soil-stone mixture samples with different water content after freeze-thaw cycles, the lower the water content, the more obvious the strain hardening; the higher the water content, the greater the effect of freeze-thaw cycles on soil-stone mixtures, and the greater the decrease in compressive strength, cohesion, and internal friction angle. * As the number of freezing and thawing cycle simulations increases, the number of internal fine cracks in the soil and rock mixture model also increases. When the number of cycles changes from 0 to 1, the number of cracks increases to 1408 due to damage caused by freezing and thawing. However, when the number of freezing and thawing cycles changes from 10 to 20, the change in the number of cracks is small, the compressive strength reduction is also small, the mechanical properties of soil and rock mixture tend to be stabilized, and the effect of the freezing and thawing cycle becomes smaller. * For different numbers of freezing and thawing cycles under the row of slopes, the stability coefficient and model fissure change rule are similar; with the increase in the number of freezing and thawing cycles, the slope stability coefficient gradually decreased from 0 to 20; the stability of the slope decreased by about 0.74, resulting in a reduction in the magnitude of about 38.54%, of which the stability coefficient occurred between 0 and 1 cycle, after which the stability began to stabilize and remained unchanged. * Under different discharging heights, the slope stability coefficient decreases with the increase in the number of freeze-thaw cycles in a power function trend; the higher the discharging height, the lower the slope stability coefficient. The slope becomes more unstable and more prone to landslides after undergoing more freeze-thaw cycles. It also has a larger impact after landslides with higher risks. Conceptualization, R.L., W.Z. and X.L. ; Data curation, Y.G. and Z.Z. ; Funding acquisition, W.Z. and X.L. ; Investigation, X.L. ; Methodology, R.L. and X.L.