地下矿山上向扇形中深孔爆破爆堆控制技术研究

Research on the Control Technology of Explosive Piles of Upward Fan-Shaped Deep Hole Blasting in Underground Mines

科学合理地控制地下矿山爆破爆堆形态,对于提高出矿效率和保障开采作业安全具有重要意义。针对上向扇形中深孔爆破中矿岩分散堆积、作业安全风险高及矿岩铲装过程复杂等问题,运用爆破破岩理论分析了岩石爆破新生自由面形成机制,并推导了形成爆破自由面的最短延期时间计算公式。采用LS-DYNA数值模拟软件构建了上向中深孔爆破FEM-SPH耦合模型,分析了不同起爆顺序的岩石爆破抛掷规律。结果表明:合理的爆破延期时间能有效地降低爆破抛掷效应,对于提升破岩效率、优化爆破块度及控制爆堆集中抛掷等具有积极作用;新生自由面在首爆孔起爆后约15~20 ms时基本成形,中间孔先起爆、两边孔后起爆的方案可显著提高爆堆集中度。研究结果可为上向扇形中深孔爆破爆堆控制提供参考。

Scientifically and reasonably controlling the explosive pile shape of underground mines is of great significance for improving mining efficiency and ensuring the safety of mining operations.In response to the problems of scattered accumulation of ore and rock,high operational safety risks,and complex mining and rock shoveling processes in upward fan-shaped deep hole blasting,the formation mechanism of newly formed free surfaces in rock blasting was analyzed using blasting rock breaking theory,and a formula for calculating the shortest delay time for forming blasting free surfaces was derived.A coupled FEM-SPH model for upward medium and deep hole blasting was constructed using LS-DYNA numerical simulation software,and the throwing laws of rock blasting with different detonation sequences were analyzed.The results show that the reasonable blasting delay time can effectively reduce blasting throwing effects,which have a positive effect on improving rock breaking efficiency,optimizing blasting fragmentation,and controlling concentrated throwing of explosive piles.The newly formed free surface is basically formed about 15-20 ms after the detonation of the first blasting hole.The scheme of detonating the middle hole first and the two side holes later can significantly improve the concentration of the explosive piles.The research results can provide a reference for the control of explosive piles in upward fan-shaped deep hole blasting.