Effect of Neighboring Hole Impacts on Inter-Hole Dynamic Presplitting Process with Consideration of Crack Width Variations

To analyze the effect of neighboring hole impacts on the inter-hole presplitting process, the dynamic cracking behavior under explosive load and ground stress is theoretically investigated by developing an inter-hole cracking model. Considering the variations in crack width, the influence mechanisms of stress waves from both in-hole and adjacent holes on the dynamic cracking process of presplitting blasting are examined through numerical simulations. Meanwhile, explosion tests under different detonation conditions were carried out to verify and further elucidate the dynamic effects of inter-hole presplitting blasting. The results indicate that the opening of presplitting holes can be restricted, reduced, or even closed during the cracking formation process due to the stress wave from adjacent holes when detonated simultaneously. Furthermore, there is a tendency for inter-hole cracks to be constrained in the large-angle direction, limiting crack propagation. And millisecond detonation timing can reduce the dynamic stress superposition effect between pre-cracked holes, thereby mitigating the damage to the surrounding rock. This finding is particularly applicable to presplitting blasting technology.