## 5 Numerical Simulation of Blasting Hole Network Parameters
### Numerical Simulation Results  
According to the simulation results of all multiple combinations of different apertures and hole spacing, the stress wave propagation law is roughly similar. This paper takes different apertures and seven times hole spacing as an example to analyze. From Figure 13a-e, it can be seen that the explosive stress wave generated by the explosion spreads outward in the form of a cylindrical wave from the starting point, and the blast wave is formed due to the impact of high-temperature and high-pressure gas produced by the explosion. The shock wave propagates upward rapidly in an 'arrow' shape. In the process of propagation, the energy density per unit area decreases rapidly due to the continuous expansion of the wave front along with the energy dissipation caused by rock failure, so the shock wave in the rock mass will gradually evolve into a compression wave and seismic wave with the increase in propagation distance. For Figure 13a, after the explosion, the stress wave propagates to the midpoint of the connection between the two blastholes, and the stress wave generated by the two blastholes meets and overlaps for the first time. The pressure generated by the explosion in the two blastholes is much larger than the dynamic compressive strength of the rock mass, and each of them forms a cavity under strong compression. The surrounding rock mass initially forms a plastic flow area, and the rock mass cracks at the superposition of the stress wave under the superposition of the stress wave. For Figure 13b, the stress wave generated by the superposition of Figure 13a continues to propagate upward and forms the 'arrow' prototype. The influence range of the stress wave in the rock mass is also increased, and the blasting energy is gradually attenuated. The plastic flow area prototype is formed around the two borehole cavities, and the stress wave continues to propagate upward. For Figure 13c, the stress wave has formed a complete 'arrow' and spread to the bottom of the plugging material, and the plastic flow area is completely formed around the two holes. Due to the large energy consumption in the stress wave propagation stage, the wave rapidly decays to a compression wave at the beginning of the next stage and continues to propagate around the bottom of the plugging material. For Figure 13d, at the interface of plastic flow zone, the explosion energy attenuates with the expansion of the propagation influence range, but it cannot be supplemented by the explosion energy; that is, the explosion energy is a continuous attenuation process. At this time, the radial compressive stress of rock mass is less than the dynamic compressive strength of rock mass, and the rock mass does not produce compressive failure. Due to  
Figure 12: Diagram of grid division. the effect of radial compressive stress, the rock mass generates tangential tensile stress. The dynamic tensile strength of rock mass is generally less than its dynamic compressive strength, and the rock mass will produce several radial tensile cracks. For Figure 13e, with the energy attenuation of the explosive gas, the radial crack propagation velocity decreases gradually until the propagation stops; due to the release of part of the elastic energy at this stage, the stress of the rock mass decreases rapidly, and the unloading wave propagating to the explosive source is generated inside the rock mass, forming the corresponding radial tensile stress, and then forming the annular crack. At this time, the stress wave array has been attenuated to be relatively flat, and the seismic wave is formed and continues to propagate to the blocked interior. The comparison Figure 13a-e shows that when the aperture of 110 mm is 0.5 ms after explosion, the influence range of stress wave is the largest. The stress wave of two boreholes meets superposition earlier than that of other boreholes, and the rock mass first cracks in the superposition area of the stress wave.