## 3 Results
### Rock Displacement Patterns Under Different Delay Time Conditions  
The Ls-PrePost (R14) software was utilized to perform box cutting on the numerical model, obtaining the post-blast half-region model of the rock mass. This approach was employed to study the internal rock mass movement and collision patterns under the influence of blasting. Under the 25 ms delay time condition, as depicted in Figure 5, it was observed that before the detonation of the second row of blast holes, the farthest movement distance of the rock mass was 0.41 m (25 ms (a1)). After the detonation of the second row of blast holes, the rock mass exhibited an upward and outward movement trend, with the overall outward movement being 1.19 m, which was only slightly larger than the 1.09 m movement observed after the first row of blast holes with a 50 ms delay, and significantly less than the 2.307 m movement under a 75 ms delay. This indicated that the short inter-row delay resulted in a weaker outward throwing effect on the rock mass. Additionally, it inhibited the movement of the internal rock mass, leading to a more pronounced restrictive effect (25 ms (b1)). Following the detonation of the third row of blast holes, the rock mass in the areas of both the first and second rows of blast holes did not effectively throw outward, creating a movement trend that restricted the outward movement of the rock mass in the area of the third row of blast holes (25 ms (c1)). After the detonation of the fifth row of blast holes, since the rock in the areas of the previous multiple rows of blast holes did not effectively throw outward, the internal rocks collided with each other and the restrictive effect became more evident, and the rock at the bottom of the upper holes was not effectively thrown out (Figure 5, 25 ms (e1)). Finally, after the detonation of the bottom holes, the throwing effect of the rock in the compensation space was worse than under the 50 ms and 75 ms delay conditions, forming a concave groove at the bottom, indicating a root phenomenon (Figure 5, 25 ms (f1)). Under the 50 ms delay time condition, as illustrated in Figure 5, it was evident that prior to the detonation of the second row of blast holes, the farthest movement distance of the rock mass was 1.09 m, exhibiting a stronger effect than the 25 ms delay but weaker than the 75 ms delay (50 ms (a2)). Upon the detonation of the second row of blast holes, the rock mass demonstrated a movement trend inclined upward at a 30\({}^{\circ}\) angle. However, compared with the 75 ms delay, the rock mass in the area of the first row of blast holes did not completely throw out, resulting in a squeezing and restrictive effect with the rock mass moving outward after the detonation of the second row of blast holes (50 ms (b2)). Following the detonation of the third row of blast holes, the movement distance of the rock mass in the area of the second row of blast holes was significantly less than that observed under the 75 ms delay, and the upper rock mass did not fully throw out, leading to a squeezing and restrictive effect with the rock mass in the area of the second row of blast holes (50 ms (c2)). After the detonation of the fourth row of blast holes, the restrictive phenomenon was pronounced but less pronounced than the 25 ms delay and more pronounced than the 75 ms delay (50 ms (d2)). Upon the detonation of the fifth row of blast holes, the rock mass at the bottom of the uppermost holes was not thrown out (50 ms (e2)). Following the detonation of the bottom holes, the throwing effect of the rock mass within the compensation space was considerably stronger than the 25 ms delay but weaker than the 75 ms delay, and a clear root phenomenon was discernible (50 ms (f2)). Figure 5: _Cont._  
Figure 5: Rock mass movement under different delay timing conditions following the detonation of blast holes.