邹庄矿井F25逆断层保护煤柱合理留设研究

Study on Reasonable Setting-up of F25 Reverse Fault Pillar in Zouzhuang Deposit

为研究大型逆断层保护煤柱留设问题,以邹庄矿井F25逆断层为工程背景,对该断层切割煤层底板奥陶系灰岩可能导致87采区煤层回采过程中断层“活化”突水情况进行分析,利用FLAC3D软件对留设不同宽度煤柱下应力场、塑性破坏区、断层带附近岩体垂向应力变化及断层“活化”规律进行了研究。结果表明,随着留设煤柱宽度变小,采动应力穿越断层带,在上盘形成应力集中区,垂向应力的演化明显滞后于水平应力;当煤柱宽度减小到20 m时,煤层顶底板表现出不同应力演化特征,且塑性破坏区与断层带导通,从而导致煤层顶断层带先于煤层底断层带“活化”,经分析得知邹庄矿井F25逆断层保留煤柱为20 m较为合理,与该矿井实际生产吻合。本研究结果为分析类似工程背景下保护煤柱留设具有一定参考价值。

It is of great significance for coal mine safety production and economic mining to reasonably set up fault protection pillars.In order to solve the problem of large-scale reverse fault protection pillar setting,F25 reverse fault in Zouzhuang Mine is taken as the engineering background to study"activation"water inrush situation of the fault.This situation may be caused by the fault′s cutting of Ordovician limestone which is from the coal seam floor.The FLAC3D software is used to study stress field,plastic failure zone and variation of vertical stress of rock mass near fault zone under coal pillars of different width.And the evolution law of fault"activation"is also studied with the help of FLAC3D software.The results show that as the width of coal pillar decreases,the mining stress passes through the fault zone and forms the stress concentration area on the upper wall,and that the evolution of vertical stress lags behind the horizontal stress obviously.When the width of coal pillar decreases to 20 meters,the roof and floor of coal seam show different stress evolution characteristics,and that the plastic failure area and fault zone are conductive,which results in the top fault zone of coal seam being"active"before the bottom fault zone of coal seam.In Zouzhuang Mine,it is more reasonable to retain the coal pillar of F25 reverse fault for 20 meters,which is consistent with the actual production of the mine.The research results provide a certain reference value for the analysis of the protection of coal pillars under similar engineering background.