根据流固耦合理论,采用有限元数值模拟的方法,针对承压水体上采煤过程中断层参数(断距、倾角)对煤层、围岩的应力、变形和水压力变化的影响进行了模拟分析,探讨了存在断层时突水的机理和可能的突水点位置,并定量分析了防水煤柱的预留距离。得出以下结论:(1)当存在正断层时,多发生断层破坏型突水,而底板破坏型突水发生的几率较小;(2)突水性质和突水发生位置受断层断距和倾角的影响不大,煤层和采煤工作面附近的底板围岩都可能成为突水涌出点;(3)随着断层断距和倾角的增加,防水煤柱的合理留设距离应随之增大。以上结果可为实际矿井采煤防突水设计提供参考。
According to the theory of coupling of solid and fluid, the influence of fault step and dip angle on the stresses and deformations of coal layer and confining rock along with the pressure of pore water are numerically simulated by finite element method during the process of excavation above a confined aquifer. The mechanism of water inrush and the potential point of water inrush arc explored. The distance of coal column for preventing water inrush is also analyzed quantitatively. The research results indicate that (1) fault-failure-type water inrush occurs more often than floor-failure-type water inrush under the existence of normal fault; (2) the influence of fault step and dip angle on the feature and position of water inrush is not evident, and water inrush may occur at both coal layer and the floor near working face; (3) the distance of coal column for preventing water inrush should be increased with the increase of fault step and dip angle. It is helpful in practical design of water inrush in coal mining.