填塞长度对单孔爆破轴向损伤分布影响研究

为研究在爆破过程中填塞长度对圆柱岩样爆破效果的影响，通过数值模拟方法建立了分区域圆柱岩样单孔装药的三维模型。通过改变填塞长度，对爆破过程中填塞物及圆柱岩样的损伤情况、位移变化和裂纹扩展进行了对比分析。结果表明：模拟结果与圆柱岩样实验室爆破裂纹扩展与损伤情况相一致，验证爆破模型可有效模拟岩石爆破过程。在填塞长度为炮孔长度的23.7%内，填塞长度的增加可显著抑制填塞物冲出炮孔程度，而超过此区间后，单位抑制效应微弱。填塞长度从炮孔长度的7.9%到39.5%，岩柱表面裂纹网络复杂程度逐渐降低，但裂隙宽度显著增加。在炸药引爆后岩柱中部区域的损伤值最高，在填塞长度为炮孔长度的23.7%时取得最高值为0.75。在岩柱上部区域，损伤随填塞长度呈现凹形变化，差值在0.0543；而五种填塞长度在岩柱中部区域的损伤差值最大，为0.0679；对岩柱下部区域的损伤影响较小，变动幅度为0.0099。填塞长度的合理选取为实现精确区域爆破和提高爆破效果提供了新的途径。

Research on the influence of stemming length on the axial damage distribution of single-hole blasting

To investigate the effect of stemming length on the blasting of cylindrical rock samples, a three-dimensional zone-divided model of cylindrical rock samples undergoing single-hole charging was established through numerical simulation methods. A comparative analysis was conducted on the damage, displacement, and crack propagation of the stemming and rock by changing the stemming lengths. The simulation results were consistent with the observed crack propagation and damage during the blasting process of the cylindrical rock samples in the laboratory, validating the effectiveness of the blasting model in simulating the rock blasting process. Within a stemming length that constitutes 23.7% of the borehole length, an increase in stemming length considerably suppresses the extent of stemming expulsion from the borehole and the unit inhibition effect diminishes beyond this range. As stemming length increases from 7.9% to 39.5% of the borehole length, the complexity of surface crack networks gradually decreases while crack width significantly increases. The highest damage value, reaching 0.75, occurs in the middle region of the rock pillar at a stemming length of 23.7% of the borehole length. In the upper region of the rock pillar, the damage shows a concave change with the stemming length, with a difference of 0.0543. Among the five stemming lengths, the largest difference in damage is observed in the middle region of the rock pillar, with a value of 0.0679. The impact of the damage in the lower region of the rock pillar is relatively small, with a variation amplitude of 0.0099. The reasonable selection of stemming length offers a new approach to achieving precise regional blasting and improving blasting effectiveness.