地应力对岩石爆破开裂及爆炸地震波的影响研究

深部岩体爆破开挖是高地应力和炸药爆炸产生的动应力共同作用的结果。采用SPH-FEM耦合数值模拟方法,研究了地应力场对岩石爆破开裂及开裂区外地震波能量的影响。结果表明:随着地应力水平的提高,岩石爆破破碎区的范围缩小、裂纹扩展速度降低,非静水地应力场中破碎区内裂纹主要沿最大主应力方向扩展,但地应力对爆破粉碎区的形成几乎没有影响;地应力作用下爆破开裂区形态改变影响了爆炸地震波的能量及传播特性,随着地应力的增大,更多的炸药爆炸能转化为地震波能量,产生的高频地震波随距离衰减更快,且小主应力方向上的爆炸地震波能量更大。研究成果可为深部岩体爆破优化设计提供理论参考。

Influences of in-situ stress on blast-induced rock fracture and seismic waves

Deep rock mass blasting excavation is due to combined effects of high in-situ stress and dynamic stress generated by explosion. Here, effects of in-situ stress field on blast-induced rock fracture and seismic wave energy outside cracked zone were investigated by using a coupled numerical simulation method called SPH-FEM. The results showed that with increase in in-situ stress level, cracked zone range narrows and crack propagation velocity drops; in a non-hydrostatic in-situ stress field, rock cracks in cracked zone mainly spread along the maximum principal stress direction, but in-situ stress almost does not affect formation of blast crushed zone; form change of blast cracked zone under in-situ stress affects energy and propagation characteristics of blast seismic waves; with increase in in-situ stress level, more explosion energy of explosives is converted into seismic wave energy, generated blast seismic waves with high frequencies decay faster with increase in distance,  and blast seismic wave energy in smaller principal stress direction  is larger;  the study results can provide a theoretical reference for optimal design of deep rock mass blasting excavation.