大落差正断层应力分析及活化规律研究

Stress Analysis and Activation Law of Normal Fault with Large Drop

基于大落差断层易造成巷道围岩严重破碎,受采掘动压影响后产生断层活化现象而不利于矿井安全生产的问题,采用FLAC3D二次开发技术优化断层模拟方法,对大落差正断层附近的应力影响范围、煤岩体破坏程度及断层活化判别标准进行了研究,揭示了大落差正断层应力分布及活化规律。结果表明:当煤层位于大断层下盘时,过断层后应力急剧上升,在短距离内达到峰值;当煤层位于断层上盘时,应力集中现象发生在下盘,在距断层一定范围内应力急剧升至峰值,而过断层后逐渐趋于平缓;断层落差越大,应力影响范围越大;埋深越大,断层应力集中程度越高,对煤岩体的破坏范围越大。研究结果不仅扩展了模拟软件的适用范围,还为大落差断层保护煤柱的留设提供了重要依据。

Based on the problem that the fault with large drop is easy to cause serious fracture of roadway surrounding rock,and fault activation phenomenon occurs after being affected by mining dynamic pressure,which is not conducive to mine safety production.FLAC3D secondary development technology was used to optimize the fault simulation method,and the influence range of stress near the normal fault with large drop,the damage degree of coal rock and the fault activation discrimination criteria were studied.The stress distribution and activation law of normal fault with large drop were revealed.The results show that when the coal seam is located at the footwall of a large fault,the stress rises sharply after passing the fault and reaches the peak value in a short distance.When the coal seam is located in the hanging wall,the stress concentration phenomenon occurs in the footwall.When it is within a certain range from the fault,the stress rises sharply to the peak value,and gradually tends to be flat after passing the fault.The larger the fault drop,the larger the influence range of stress.The greater the burial depth,the higher the fault stress concentration,and the larger the damage range to coal rock.The research results not only expand the application scope of the simulation software,but also provide an important basis for the retention of protective coal pillars in normal fault with large drop.