Blasting, Volume. 42, Issue 3, 86(2025)
Research and Application of Dispersed Charge Pre-splitting Blasting Technology for Uniform Fracturing Composite Roof
Differences in thickness, mineral composition, wave impedance, and joint fissures. This often leads to a mismatch between the charge structure of the pre-splitting and cutting holes and the physical and mechanical properties of the layers, which can easily cause the complex rock layers to fail to pre-split. The soft rock layers form chicken-nest-shaped explosive pits due to excessive consumption of explosive energy, making it difficult for pre-splitting and cutting holes to penetrate the entire length of the blast hole effectively. To attain consistent pre-splitting of the composite roof, the LS-DYNA software was employed to analyze the impact of the charging structure on the pre-splitting effect of the composite roof. Based on this foundation, a uniform-dispersion and pressure-holding pre-splitting blasting technique was proposed for the composite roof. Field experiments were conducted, and in conjunction with the preliminary evaluation of the progression of post-blast fractures, the viability of this uniform-dispersion and pressure-holding pre-splitting blasting method was substantiated. The research results indicate that the escape of explosive gas from hard rock layers to soft rock layers is the primary reason for the uneven energy utilization in the pre-cracking explosion of the composite roof. The composite roof uniform dispersion pressure pre-splitting blasting technology divides the pre-splitting holes into multiple chambers according to the layered structure of the composite roof. Each layer has an independent post-explosion pressure holding chamber, which meets the explosive energy requirements of each pre-splitting layer, thereby avoiding excessive consumption of explosive energy in soft rock layers and enhancing the pre-splitting effect in hard rock layers.
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ZHANG Zhi-zhong, LIU Yu-shan, ZHANG Xue-feng, HAO Bing-yuan, WANG Chen-long, ZHANG Tao. Research and Application of Dispersed Charge Pre-splitting Blasting Technology for Uniform Fracturing Composite Roof[J]. Blasting, 2025, 42(3): 86
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Received: Sep. 27, 2024
Accepted: Sep. 18, 2025
Published Online: Sep. 18, 2025
The Author Email: ZHANG Tao (962941834@qq.com)