瓦斯抽采钻孔破坏过程数值分析

Numerical analysis of destroy process of gas extraction Hole

从瓦斯抽采过程中钻孔的塌孔卡钻现象出发,结合RFPA2D-Flow模拟结果,分析说明了由于应力集中现象的出现,对钻孔周边煤体中瓦斯渗透率的影响,并根据钻孔周边应力沿孔壁的变化规律得出了瓦斯沿抽放钻孔周边涌出的发展规律.最后,通过对钻孔周边应力沿孔壁的变化规律和瓦斯涌出时导致的卸压作用的分析,得出了瓦斯抽放钻孔周边煤岩体的破坏是由上下两侧孔壁首先被拉裂然后导致破坏向左右两侧孔壁逐渐延伸的发展过程.

Starting from the phenomenon of holes subsiding and driller blocking m gas aramage process, mrougn the analysis of the results of theoretical calculation and numerical simulation of RFPA2D-Flow, this study analyzed the influence of stress-focus phenomenon on gas permeability of coal body around the hole, and derived the gas emission development law from drilling inner wall through the analysis of the stresses distribution of coal body around the drainage hole. At last, the failure process of coal body around the drainage hole was given through analysis of the stresses distribution of coal body around the drainage holes and the stress-relief role caused by gas emission.