深井高应力岩体精确延时爆破破岩机理研究

Large scale blasting in deep mining broke the stress balance of rock masses with high energy stored inside, and leads to transient unloading of in-situ stress. However, the present studies mostly focused on catastrophic effect caused by passively energy release of transient unloading, and the possibility of converting from transient unloading energy to effective crushing energy was ignored. Aiming at initiatively controlling and efficiently using of elastic strain energy stored in highly stressed rock masses, delay blasting with precise initiation based on electronic detonators and several research methods including theoretical analysis, laboratory test, field test and numerical simulation would be adopted. First, by analyzing the propagation characteristics and attenuation laws of explosive shock wave and transient unloading wave, the energy-transfer and coupling mechanism of these two waves are obtained. Then the influence of delay time on blasting effect in highly stressed rock masses is investigated. At last, precise delay blasting technique will be put forward to achieve efficient use of elastic strain energy stored in deep rock masses and vibration reduction. The study contributes a better understanding about rock breaking mechanism of highly stressed rock masses, and it is important to guide blasting parameters optimization and disaster prevention in deep mining. In addition, the study provides a scientific basis for application of precise delay blasting in highly stressed rock masses.

深井规模爆破打破了高储能原岩的应力平衡并触发应变能瞬态调整，目前研究主要集中于高应力岩体弹性应变能被动释放诱发的灾变效应，而忽略了岩体瞬态卸荷能转化为爆破有效破碎能的可能。本项目针对深井矿岩应变能主动调控与合理利用这一核心问题开展研究，采用基于电子雷管的精确延时起爆为技术手段，结合理论分析、室内模型实验、现场试验及数值模拟等方法，首先基于实测应变波形分析爆炸冲击波和瞬态卸荷应力波的传播特征与衰减规律，揭示高应力岩体爆炸冲击波与瞬态卸荷应力波的能量传递规律与耦合作用机制，继而研究精确延期时间对高应力岩体爆破作用的影响规律，在此基础上研发实现深井矿岩高储能合理利用的精确延时爆破破岩方法及降振技术。研究成果有助于加深对高应力岩体爆破破岩机理的认识，对指导深井矿岩爆破参数优化与灾害预防具有重要的现实意义，可为精确延时爆破技术的推广应用提供理论基础与科学依据。

深井矿山高地应力环境给资源安全高效开发带来了严峻的挑战。深部高地应力环境改变了矿岩的动态力学性能、变形破坏特征及能量耗散规律，进而影响岩石破裂过程及破碎特征。地应力对岩石爆破破岩的影响不容忽视，在爆炸荷载作用下，地应力岩体受到静态围岩压力荷载和动态爆炸荷载的耦合作用，其爆破破岩机理有别于单纯的静载或动载下的破坏机理。采用理论解析、模型实验、数值模拟、现场试验等方法，深入开展高地应力环境下岩石爆破破岩机理研究，理论探索静应力与三维球腔爆炸荷载耦合应力场时空演化机制和围压作用下应力波在自由面的压屈破坏，开展静应力下不同抵抗线单孔和双孔爆破漏斗模型试验，揭示地应力对岩石爆破破岩过程的影响机制，最后结合现场工业试验给出了深井高应力矿山采场爆破优化方案。项目发表SCI论文10余篇，授权发明专利7项。