## 4 Optimization of Blasting Parameters
### Numerical Simulation Verification
#### 4.3.3. Conducting Comparative Analysis on Model Failure  
In order to compare and analyze the influence of hole spacing and row spacing on slope step blasting, the maximum principal stress distribution of the three models is illustrated in Figure 15. The hole spacing for group (a) is 4 m and 3.46 m, for group (b) is 4.62 m and 4 m, and for group (c) is 5 m and 4.33 m. (a) After blasting, the maximum stress at the gun hole location reaches 1.543 \(\times\) 10\({}^{5}\) N, while the maximum principal stress at the middle and back sections amounts to 6 \(\times\) 10\({}^{4}\) N. The stress distribution exhibits unevenness with a concentration area, where significant stress occurs in the rear rock mass. (b) Following blasting, the maximum stress at the gun hole location measures up to 1.542 \(\times\) 10\({}^{5}\) N; however, there exists small residual stress in both the middle and back parts of the rock mass with an evenly distributed pattern. (c) For group (c), after blasting, it shows a peak value of approximately 1.554 \(\times\) 10\({}^{5}\) N at the gun hole location as well as a maximum principal stress reaching around 8 \(\times\) 10\({}^{4}\) N in its middle and back sections, which also exhibit some degree of concentration. By comparing these cloud images, it can be observed that within a range of approximately 20 m-40 m from the upper edge of the step area, the level of stress experienced by group (b) is significantly lower than that encountered by both groups (a) and (c). This indicates that due to minimal damage effects on the intact rock mass behind caused by blasting operations, group (b) demonstrates better suitability for mining production and construction purposes. The level of stress at the back end of group (c) is less than that of group (a), but it is more pronounced than that of group (b). Therefore, it can better adapt for rock mining and production compared to groups (a) and (c).  
The acceleration changes in groups (a), (b), and (c) at 30 m on the edge of the step within 1 s of blasting time are illustrated in Figure 16. It can be observed from the figure that group (a) achieves a maximum acceleration of 0.185 m/s\({}^{2}\) at 0.009 s, while group (b) reaches a peak acceleration of 0.176 m/s\({}^{2}\) at the same time. Group (c), on the other hand, attains its maximum value at 0.009 s, with a peak acceleration of 0.183 m/s\({}^{2}\). Similarly, among the three simulation groups, group (b) experiences the smallest peak acceleration,  
Figure 15. Results of maximum principal stress distribution in groups (**a–c**).  
indicating that the rock mass behind it bears minimal stress and exhibits good stability, which is favorable for subsequent construction.  
The velocity changes at 30 m on the upper edge of the slope step for groups (a), (b), and (c) within 1 s of the blasting record time are depicted in Figure 17. It can be observed from the figure that group (a) reaches a maximum velocity of 0.022 m/s, after which it starts to decline. Group (b) attains a maximum velocity of 0.013 m/s, peaking at 0.045 s before declining thereafter. Group (c) achieves a maximum speed of 0.023 m/s towards the end. Consequently, it can be concluded that among these three groups simulating slope step blasting, group (b) exhibits a minimal impact on the farthest measurement point from the blast hole location, specifically on the upper edge of the slope step, thus indicating that group (b) inflicts less damage to the intact rock mass behind its post-blasting.  
The above idealized model research experiments demonstrate that the enhanced Gray Wolf algorithm is employed for optimizing blasting parameters in mining slopes with simple lithology and structural planes, resulting in improved blasting effectiveness and cost optimization.