断层影响下底板突水通道研究

Study on Water Inrush Passage from Floor Affected by Fault

基于岩体极限平衡理论,综合考虑断层本身性质和矿山压力中应力降低区的作用,解得底板隔水层的极限水压解析式,推导出底板突水力学判据,结合华泰煤矿7502工作面,解得底板隔水层的极限水压大于实际承压水水压,底板隔水层中没有形成突水通道;基于FLAC3D流固耦合理论,建立了断层影响下煤层开采的数值模型,得出断层带中的承压水导升高度(8m)较正常岩层(6m)高,断层影响下底板岩体应力呈非对称分布,断层附近的底板采动破坏深度(24m)大于未受断层影响的底板破坏深度(20m),底板破坏区与断层导通,承压水通过断层进入破坏区,形成突水通道,发生底板突水。结果表明:断层影响下的底板突水,往往不是底板隔水层破坏导致,而是承压水通过断层进入采动破坏区所致。

Based on the theory of rock mass limit equilibrium, considering fault nature and stress decreasing zone of mining pressure, the paper obtained analytic formula of the water resisting floor＇s limit pressure, deduced the hydraulic criterion for floor water inrush. Combining with the condition of 7502 working face Huatai Coal Mine, the calculation showed the limit pressure of floor aquifuge was greater than the actual confined water pressure, so water inrush channel was not formed in floor aquifuge. Based on the fluid structure interaction theory of FLAC3D, a numerical simulation model of coal seam under the influence of fault was built. The height of confined water in fault zone （8m） was higher than in normal rock （6m）; stress distribution of floor rock mass under the influence of fault was asymmetric; the mining failure depth near fault （24m） was greater than the unaffected （20m）. Confined water flowed into the damage area through fault, forming the water - inrush passage. The results show that, floor water inrush under fault, is not much often caused by floor aquifuge failure, but the confined water influx into the mining failure area through fault.