深部岩体爆破爆炸地震波辐射模式与能量特性数值模拟研究

• 作 者: 杨建华 吴泽南 孙文彬 姚池 王秋慧
• 出 处: 中南大学学报（英文版）
• 发表日期: 2022年2期
• 关键词: blasting in-situ stress seismic wave rock fracture SPH-FEM

对于深部岩体爆破,普遍认为地应力的存在将改变爆生裂纹的传播过程并最终影响岩体爆破开裂区的分布,但对于地应力作用下岩体爆破开裂区形态改变对爆炸地震波辐射模式的影响,目前还鲜有研究报道.本文采用SPH-FEM耦合数值模拟方法,研究了地应力对岩体爆破开裂及爆炸地震波辐射模式和能量特性的影响.结果表明,在地应力作用下岩体爆破开裂区形态改变对爆炸地震波能量及组成成分具有显著的影响;随着地应力水平的提高,岩体爆破开裂区范围缩小,更多的爆炸能转化为地震波能量,地应力作用下爆破开裂区(即爆炸地震波产生区)范围缩小导致地震波的频率升高;在非静水地应力条件下,沿最小主应力方向传播的爆生裂纹更易受到地应力的抑制,因此沿该方向传播的地震波的能量密度更高;在非静水地应力条件下各向异性的岩体爆破开裂模式导致岩体应变能非对称地快速释放,从而在岩体中诱发剪切波.“,”With regard to blasting in deep rock masses, it is commonly thought that an increase in the in-situ stress will change the blast-induced rock crack propagation and ultimately affect rock fragmentation. However, little attention has been given to the change in seismic wave radiation when the fractured zone changes with the in-situ stress. In this study, the influences of in-situ stress on blast-induced rock fracture and seismic wave radiation are numerically investigated by a coupled SPH-FEM simulation method. The results show that the change in blast-induced rock fracture with in-situ stress has a considerable effect on the seismic wave energy and composition. As the in-situ stress level increases, the size of the fractured zone is significantly reduced, and more explosion energy is transformed into seismic energy. A reduction in the size of the fractured zone (seismic wave source zone) results in a higher frequency content of the seismic waves. In a nonhydrostatic in-situ stress field, blast-induced cracks are most suppressed in the direction of the minimum in-situ stress, and thus the seismic waves generated in this direction have the highest energy density. In addition to P-waves, S-waves are also generated when a circular explosive is detonated in a nonhydrostatic in-situ stress field. The S-waves result from the asymmetrical release of rock strain energy due to the anisotropic blast-induced fracture pattern.