Analysis and Study on the Patterns of Microseismic Activity in Fully Mechanized Top-Coal Caving Face under the Influence of Zigzag Fault Coal Pillar

When mining along irregular coal pillars along faults in a fully mechanized top coal caving face in a short distance coal seam, it is easy to form a stress concentration area. Analyzing and studying the microseismic activity rules during mining can help to grasp the roof movement rules and reduce the risk of rock burst. Therefore, taking Zhaolou Coal Mine 7301 fully mechanized top coal caving face as an example, this paper studies the microseismic activity rule of a kilometer deep fully mechanized top coal caving face in Juye Mining Area under the influence of sawtooth shaped fault coal pillars, and discusses the impact of different mining speeds on microseismic activity and rock pressure behavior rule under the joint influence of faults and coal pillars. Based on the analysis of the spatial distribution of microseismic events and on-site monitoring data in 7301 working face, the main conclusions are as follows: According to the variation rules of the main indicators of microseismic events, the periodic weighting is divided into two types, the first type being a single break type, and the second type being a multiple break type; There is a relatively significant event density phenomenon in the working face, and the three event density distribution regions can better reveal the stress distribution state; A large number of microseismic events occurred in, above, and below the fault coal pillar on the north side of the transportation trough, indicating that the surrounding rock is in an unstable state, and mining activities may cause certain dislocation of the fault; When the pushing and mining speed exceeds 5 m/d, there is a significant increase in microseismic energy relative to the pushing and mining speed less than 5 m/d. The reasonable inferred speed obtained provides a reference for working faces under similar conditions.