## 3 Analysis of Numerical Simulation Results
### Stress-Strain Curves  
Figure 6 shows the stress-strain curves of the rock under different schemes. During the tensile loading simulation of the rock model under different schemes, the stress-strain curves show obvious stage characteristics. In the elastic stage, the stress and strain have a linear relationship, and the rock exhibits elastic deformation characteristics. The slope of the curve in this stage remains basically unchanged, and this slope is the elastic modulus of the rock. As the loading continues, when the stress reaches a certain level, microcracks begin to initiate and propagate inside the rock, and the curve gradually deviates from the linear relationship and enters the elastoplastic stage. At this time, the stress growth rate gradually slows down. When the crack propagates to a certain extent, the rock reaches its peak strength and then enters the post-peak stage. The stress starts to decline, the strain continues to increase, and the rock fails and is accompanied by large deformation. Figure 6: Stress–strain curves under different schemes. (**a**) Scheme A; (**b**) Scheme B. For the case of different pore percentages in Scheme A, the stress-strain curve of Scheme A1 (\(P_{\rm por}=1\%\)) has a relatively large slope in the elastic stage, indicating that its elastic modulus is relatively high. This is because the low porosity makes the internal structure of the rock relatively complete, and the connection between particles is relatively tight, resulting in a strong resistance to deformation. Its peak strength is the highest among all in Scheme A, reaching about 373 KPa. In the post-peak stage, the stress decreases relatively slowly, showing a certain ductility characteristic. This is because although a small number of pores can cause crack propagation, the damage to the overall structure is relatively limited, and the crack propagation process is relatively stable. The elastic modulus of Scheme A2 (\(P_{\rm por}=2\%\)) is lower than that of A1, and the slope of the curve in the elastic stage becomes smaller. This is because the increase in the number of pores weakens the internal connection of the rock. Its peak strength drops to about 359 KPa, the stress decreases faster in the post-peak stage, and the ductility decreases. This shows that the increase in pores accelerates the crack propagation and interaction, making the rock failure process more rapid. The elastic modulus of Scheme A3 (\(P_{\rm por}=3\%\)) further decreases, and the linearity of the stress-strain curve in the elastic stage is significantly reduced. The peak strength is about 338 KPa, and the stress drops sharply in the post-peak stage, almost showing a brittle failure characteristic. This is because the higher pore percentage makes the internal structure of the rock porous, and a large number of microcracks start to initiate and connect at a lower stress, resulting in a rapid loss of the rock's bearing capacity. The elastic modulus of Scheme A4 (\(P_{\rm por}=4\%\)) is extremely low, and the curve has already shown obvious nonlinearity in the elastic stage. The peak strength is only about 303 KPa. In the post-peak stage, the stress quickly approaches zero, and the rock shows a typical brittle failure. This indicates that the pores have a very significant deterioration effect on the mechanical properties of the rock at this time, and the rock can hardly withstand large deformation. In the case of different pore sizes in Scheme B, the stress-strain curve of Scheme B1 (\((d_{\rm min}\), \(d_{\rm max})=(0.0005\), 0.001) m) has a relatively small slope in the elastic stage due to the small pore size and large number, and the elastic modulus is low. This is because the weakening effect of many small pores on the rock structure is relatively dispersed. Its peak strength is about 370 KPa. In the post-peak stage, the stress decreases in a complex manner, showing a multi-stage fluctuating downward trend.