正断层上、下盘开采冲击地压危险性数值模拟研究

Numerical Simulation Research on Rockburst Risk of Mining in Hanging or Foot Wall of Normal Fault

为得出断层对工作面开采过程的影响,借助数值模拟方法研究了正断层条件下工作面分别位于上盘或下盘开采时冲击地压发生的危险性。将工作面布置在上盘,研究了工作面开采过程断层面不同位置处应力及滑移量变化过程,得出了工作面距断层10~80 m内断层活化程度及冲击地压危险性;将工作面布置于下盘,研究了相同条件下下盘开采时的应力分布及变形量演化规律;通过2种条件下危险性的对比分析,结果表明开采过程会对断层产生影响并导致断层面处应力的变化,且工作面越靠近断层影响程度越大;下盘开采时顶板处的滑移量是上盘开采的2.4~3.2倍,最易导致断层的活化,因此发生冲击地压的危险性最大。

To obtain the influence of mining to fault,the risk of rockburst was studied when mining in hanging or foot wall of normal fault with numerical simulation.The working face was arranged in hanging wall,the variations of stress and slip at different positions of the fault plane were studied during mining,and the activation degree of the fault and rockburst risk were obtained within the distance between 10 and 80 m from fault to working face.The stress distribution and deformation evolution were studied when mining in foot wall under the same conditions.Compared to the two situations,the results show that mining will affect the fault and lead to the change of stress at the fault plane,and the closer the working face is to the fault,the greater the influence is.During foot wall mining,the slip at the roof is 2.4 to 3.2 times that of hanging wall mining,which is most likely to lead to fault activation,so the risk of rockburst is the greatest.