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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.
Based on the phenomenon of hole collapse stuck during gas drainage and the RFPA2D-Flow simulation results, the paper analyzes the influence of stress concentration on the gas permeability in the coal surrounding the borehole, The rule of the development of gas emission along the perimeter of the drainage hole is obtained by the variation law of the surrounding stress along the hole wall.Finally, through the analysis of the variation regularity of the stress along the hole wall and the relief effect caused by gas emission It is concluded that the destruction of the coal and rock mass around the gas drainage borehole is caused by the first fracture of the pore walls at the upper and lower sides and the consequent extension of the pore walls to the left and right.