爆生气体对高应力低透气性煤层深孔爆破增透影响的数值模拟

Numerical Simulation for Influence of Detonation Gas on Increasing Permeability of Coalseam with High-stress and Low-permeabiligy by Deep-hole Blasting

考虑爆炸波和爆生气体时程荷载,采用FLAC3D有限差分动力模块,模拟了衰减规律不同的爆生气体对高应力高瓦斯低透煤层深孔爆破裂纹扩展的影响。其中,随裂纹扩展的时间和速度而衰减的爆生气体时程荷载,既作用在炮孔壁上又作用在爆生裂纹表面。研究结果表明:爆生气体在深埋高应力低透气性煤层深孔爆破致裂过程中起主要的驱动作用,煤层增透的效果随爆生气体衰减速度的降低而显著增加;高量爆生气体的低爆速炸药的研发对高应力高瓦斯低透煤层深孔爆破增透的现实意义重大。

Using dynamic module of FLAC3D and applying time-histories load of blasting wave and detonation gas, influence of detona-tion gas with different attenuation rule on fissure extension of coalseam with high-stress and low-permeability by deep-hole blasting was simulated. The time-histories load of detonation gas which attenuated with time and speed of fissure extension was exerted on bore-hole wall and fissure faces. Results showed that detonation gas played main activation role in fissure extension of coalseam with high-stress and low-permeability. The effect of increasing coalseam permeability observably rose with attenuation speed of detonation gas fell. It is very important that developing explosive with low detonation velocity which can produce large amount of detonation gas for increasing permeability of coalsam with high-stress and low-permeability.