The stability of crown pillar is critical during the transition from open pit to underground mining. Mining-induced fractures in the pillar form water seepage channels, which can cause potential water inrush hazards. A microseismicity-based method to establish seepage channel network and assess damage state of rock mass in the pillar is proposed. The formation processes of seepage channels and associated rock failure mechanism were analyzed. First, the spatiotemporal evolution of the microseismic (MS) events was presented, based on which the development process of the fractured zone was determined. Second, moment tensor inversion (MTI) was utilized to interpret the focal mechanism of the MS events. A 3D rose diagram was utilized to measure the fracture orientations and determine the main fracture surfaces, and a fracture network was subsequently established. Meanwhile, the distribution characteristics of the fracture radii and volumes were discussed. The results show that shear fractures were dominant in pillar and accounted for more than 90% of all MS events. The overall damage tensor of the pillar was subsequently assessed based on the MS-derived fractures, and the maximum damage direction was determined. Third, a fast chronological expansion method was proposed to iteratively build a connected network with a combination of MS event locations and the corresponding fracture orientations. The MS-derived connected network was used to estimate the distances of event-to-event seepage, from which the shortest seepage channel from each individual event to the network was determined in chronological order. Seepage channels between hydraulic recharge and discharge points were inferred. These results could be helpful for better characterization of seepage channel development and the implementation of pillar reinforcement.

在从露天开采到地下开采的过渡过程中，冠柱的稳定性至关重要。矿柱中的采矿引起的裂缝形成渗水通道，这可能导致潜在的突水危险。提出了一种基于微震的方法来建立渗流通道网络并评估柱内岩体的破坏状态。分析了渗流通道的形成过程及相关的岩石破坏机制。首先，介绍了微震事件的时空演化，在此基础上确定了裂缝带的发育过程。其次，利用矩张量反演 (MTI) 来解释MS 事件的聚焦机制。3D玫瑰图用于测量裂缝方向并确定主要断裂面，随后建立断裂网络。同时，讨论了裂缝半径和体积的分布特征。结果表明，剪切断裂在柱体中占主导地位，占所有 MS 事件的 90% 以上。整体损伤张量随后根据 MS 衍生的裂缝评估支柱的破坏，并确定最大损坏方向。第三，提出了一种快速按时间顺序扩展的方法，以迭代地构建具有 MS 事件位置和相应裂缝方向组合的连接网络。MS衍生的连通网络用于估计事件到事件渗流的距离，从中按时间顺序确定从每个单独事件到网络的最短渗流通道。推断液压补给点和排放点之间的渗流通道。这些结果有助于更好地表征渗流通道的发展和支柱加固的实施。