深部岩体爆破冲击波能量分布特征

Energy Distribution of Shock Wave in Deep Rock Mass Blasting

地应力对岩体爆炸应力与爆炸能量的分布有重要影响。针对深部岩体爆破冲击波能量分布,基于叠加原理,计算地应力和爆炸荷载双重作用下岩体爆炸应力分布,结合岩体破坏准则,得到了冲击波作用下深部岩体的破坏特征,分析不同工况下传递入深部岩体引起爆破扩腔、径向裂隙扩张及岩石弹性变形的冲击波能量占比,采用数值模拟方法探究了地应力对岩体爆破冲击波能量分布的影响。研究结果表明:岩体性质、炸药性能及地应力水平均会对深部岩体冲击波能量分布产生显著影响;高地应力环境下,硝铵炸药传递入硬岩(花岗岩)的冲击波总能量占比及有效能量的占比较于软岩(页岩)更小,与低性能炸药相比,采用高性能炸药爆破时传递入花岗岩的冲击波总能量占比及有效能量的占比更大;随地应力增大,用于爆腔膨胀的冲击波能量占比基本不变,用于裂隙扩张的冲击波能量占比近似呈线性减小,用于引起弹性变形的冲击波能量占比近似呈指数增长;高地应力环境下,传递入岩体的冲击波总能量占比虽然较大,但有效能量的占比较小;研究成果可为改善深部岩体爆破冲击波能量分布及提升岩体爆破效果提供参考。

In-situ stress has a significant effect on the distributions of the rock mass stress induced by explosion and the explosion energy.To elucidate the distribution characteristics of explosion energy in deep rock mass,the distribution of rock mass stress under the action of in-situ stress and explosion load is calculated using the superposition principle.Subsequently,the failure characteristics of deep rock mass under shock waves are determined using the rock mass failure criterion.The proportions of shock wave energy that causes blasting cavity expansion,radial crack propagation,and rock mass elastic deformation under different conditions are analyzed.Furthermore,a numerical simulation method is employed to investigate the impact of in-situ stress on the distribution of shock wave energy in the rock mass.The results demonstrate that the characteristics of rock mass,the performance of explosive,and the levels of in-situ stress significantly affect the energy distribution.The proportion of total energy of shock waves transmitted into hard rock(granite)and the proportion of effective energy are smaller than those in soft rock(shale)under high in-situ stress environment.Compared with low-performance explosives,when using high-performance explosives for blasting,the proportion of total energy of shock waves transmitted into granite and the proportion of effective energy are greater.With the increase of in-situ stress,the proportion of shock wave energy for the blasting cavity expansion is basically unchanged,the proportion of shock wave energy for radial crack propagation decreases linearly,and the proportion of shock wave energy for rock mass elastic deformation increases exponentially.The effective energy is relatively small although the proportion of the total energy of shock waves is larger under the higher in-situ stress.The findings can provide a reference for improving the energy distribution of shock wave in deep rock mass blasting and enhancing the blasting effect of rock mass.