In order to study the pressure relief distribution characteristics of coalbed methane in goaf, we use FLAC3D software to simulate the three -dimensional stress distribution of the surrounding rock after excavation of coal seam. The distribution characteristics of the unloading space in goaf are divided based on the calculation results. The results show that the distance from the center of the coal seam increases, and the stress in the vertical direction increases sharply, then the velocity increases slowly until it approaches to the stress of the original rock; with the increase of the distance from the boundary of the goaf, the triaxial stress on the coal pillar increases sharply first, then decreases sharply and gradually tends to the original rock stress; the overall distribution of the unloading space in goaf is approximately "crab", and the unloading space of the goaf in the upper part of the coal seam is obviously greater than that in the lower part.%为研究采空区的采动卸压空间分布特征,采用FLAC3D软件模拟计算煤层开挖后围岩的三维应力分布,并基于计算结果划分出采空区的卸压空间分布特征.结果表明:离开采煤层中心距离增加,竖直方向应力先急剧增大,随后增加速度缓慢直至趋近原岩应力;离采空区边界距离增加,煤柱上的三向应力先急剧增加,再急剧降低并逐渐趋于原岩应力;采空区卸压空间分布整体呈现近似"螃蟹形",且开采煤层上部的采空区卸压空间明显大于下部.
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