采动影响下逆断层特征参数对断层活化的作用规律

Influence law of fault activation induced by coal extraction based on characteristic parameters of thrust fault

笔者分析了采动影响下断层滑移的主要影响因素,以数值模拟为研究手段,利用FLAC3D建立了逆断层简化模型,分析了不同断层倾角、不同落差及采掘工作面与断层不同距离的断层带附近煤岩体弹性能、断层面正应力与剪应力、断层滑移量的变化规律,从而揭示了采动影响下逆断层特征参数对断层活化的基本作用规律。研究结果表明:上盘或下盘开采,断层带附近煤岩体弹性能集中程度随工作面与断层距离的增大而降低,随断层倾角及落差的增加而增大,但下盘开采对断层带的能量集中程度较上盘高。下盘开采时剪应力较上盘显著增加,但正应力变化较小,易于断层活化。上盘或下盘开采,随工作面与断层距离的增加,断层滑移量减小。上盘开采,随断层倾角增大,断层滑移量增加;随断层落差增大,断层滑移量减小。下盘开采,随断层倾角增大,断层滑移量减小;随断层落差的增大,断层滑移量增加。

The main factors of fault slip are analyzed in this paper.A simplified model of thrust fault is constructed by FLAC3 Dand the basic change law of elastic energy,vertical stress,shear stress and slippage of fault plane in the conditions of different distance from the fault,different fault dips and different throws is analyzed.And then the influence law of fault activation induced by coal extraction based on the characteristic parameters of thrust faults is revealed.The study results show that the elastic energy near faults will decrease with the distance increases from faults and will increase with fault dips or fault throws increase in the hanging wall or the footwall mining.But the focus level of elastic energy is high in the footwall mining.Vertical stress and shear stress variation of the different characteristic parameters is complicated.In a word,the increase of shear stress is obvious and the variation of vertical stress is not obvious.And the situation is prone to faults activation.Fault slippage will decrease with the distanceincrease from faults in the hanging wall mining or the footwall mining.And fault slippage will increase with fault dips increase and will decrease with fault throws increase in the hanging mining.If faces are mined in the footwall,the reverse results will show.