Abstract The intricate distribution of fractures in rock mass leads to the anisotropy of permeability characteristics of the rock mass, which affects the overall stability of rock mass. Aiming at the water inrush from floor in the deep mining of the Dongjiahe coal mine, the distribution and development law of fractures in coal mine rock mass are determined by combining the acoustic emission information from the RFPA software and the in-site microseismic monitoring data. The representative element volume (REV) of permeability of fractured rock mass is determined by numerical simulation. The results show that: (1) As the increase of surrounding rock pressure, the permeability coefficient is decreasing, as well as the principal values of permeability. (2) Under the same surrounding rock pressure, the surrounding rock pressure has little influence on the principal directions of permeability; when the surrounding rock pressure is different, the principal directions of permeability changes greatly with the change of surrounding rock pressure. (3) With the increase of the trace length, the principal values of permeability dramatically increase and the size of REV gradually decreases. When the trace length reaches a certain size, the influence on the REV can be ignored.

中文翻译：

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裂隙岩体渗透特性——以董家河煤矿为例

摘要 岩体中裂缝的复杂分布导致岩体渗透特性的各向异性，影响岩体的整体稳定性。针对董家河煤矿深部开采底板突水，结合RFPA软件声发射信息和现场微地震监测数据，确定了煤矿岩体裂缝的分布及发育规律。裂隙岩体渗透率的代表单元体积（REV）由数值模拟确定。结果表明： (1)随着围岩压力的增加，渗透系数减小，渗透率主值减小。(2) 在相同的围岩压力下，围岩压力对渗透率主方向影响不大；当围岩压力不同时，渗透率主方向随着围岩压力的变化而发生较大变化。(3)随着迹线长度的增加，渗透率主值急剧增加，REV大小逐渐减小。当走线长度达到一定尺寸时，可以忽略对 REV 的影响。