工作面回采与断层活化的相互影响分析

对断层活化进行了数值模拟,并分析了断层活化与工作面回采的相互影响。得出如下规律:当断层面的切向应力达到断层的抗剪强度时,断层便进入非稳定的临界状态,此时轻微扰动便可能导致断层活化,释放巨大能量。开采引起的库伦应力增量Δσm是断层活化的主要原因,断层活化概率增益与Δσm成正比。工作面从断层上盘向断层面推进时,断层面法向应力和切向应力都逐渐增大。工作面从断层上盘向断层面推进时,整体上断层面法向应力下降,切向应力上升,这都导致了断层的活化。工作面回采与断层活化是相互影响的两个方面,工作面开采会引起断层应力场的变化继而导致断层活化,断层的活化反过来又对工作面产生影响。

Mutual Influence of Mining and Fault Activation

This paper analyzed mutual influence of fault activation and mining by numerical simulation.When tangential stress increased to shear strength,fault reached critical state of instability,minor disturbing would result in fault activation and release energy at this time.Coulomb stress increment Δσm was main reason of fault activation and probability of fault activation was proportional to Δσm.When mining face advancing to fault from fault’s hanging wall,normal and tangential stress on fault plane both increased.When mining face advancing to fault from fault’s footwall,normal stress decreased and tangential stress increased,this resulted in fault activation.One side,mining might change stress field of fault and result in fault activation.On the other side,fault activation might influence mining.