起爆位置对煤岩体深孔爆破的影响

基于岩石断裂力学和爆炸力学原理,分析了起爆位置对深孔爆破效果的影响。并运用有限元软件ANSYS/LS-DYNA,对不同起爆位置下柱状药包在煤岩体中产生的应力场及其传播规律进行三维数值模拟研究。研究结果表明:起爆位置对深孔爆破有显著影响,孔口起爆形成的爆炸高能区指向煤岩体内部,有利于炮孔底部深部岩体的瞬时脆性断裂,孔底起爆在煤岩体内形成的应力有效冲量是孔口起爆1.5倍左右,有利于塑性区内应力集中区煤岩体的破碎和裂纹扩展。

The Influence Research of Initiating Position on Deep-hole Blasting Among Coal-rock Masses

Based on rock fracture mechanics and explosion mechanics principle,the paper analyzes the influence of initiating position on deep-hole blasting.And with the help of finite element software ANSYS/ LS-DYNA,using three-dimensional numerical simulation,the paper studies cylindrical charge stress field and propagation rule among the coal and rock produced by different initiating position.The results show that initiation position has significant effect on deep-hole blasting when high-energy area of orifice initiating points to coal-rock mass inside.It is useful to instantaneous brittle fracture of blast hole deep rocks.Compared with orifice primes,hole-bottom primes that produces effective-stress impulse in coal-rock masses is about 1.5 times,which is conducive to crushing and crack propagation in the plastic stress concentration zone of coal-rock masses.The results have important theoretical and practical value,which further reveal the mechanism of deep hole blasting,improve the effectiveness of prevention and control of coal and rock dynamical disasters and increase permeability of the low permeability coal seam with blasting.