深部开采应力场时空分布与矿震孕灾机理

Time-space Distribution of Mining Stress Field and Disaster-pregnant Mechanism of Mine Quake in Deep Mining

针对深部开采问题,运用理论分析、微震监测、数值模拟相结合的研究手段,研究了深部采动应力场时空分布规律及对矿震孕灾过程的控制机理。研究表明:震源点在工作面前方和采空区后方积聚,工作面前方要多于采空区后方,并且主要集中在裂隙带附近和应力增高区附近;震源点随着工作面推进先是在老顶积聚,后逐渐向上方岩层发展,等到开采后又再次降低到老顶附近。矿震的发生要经过平稳期、孕育期、应力(能量)激增期三个阶段。在这个阶段,受到地质构造和开采条件的影响下,应力的重新分布,产生应力集中并积聚大量的弹性能,并向局部区域转移。在扰动条件下,变性能瞬间释放从而产生矿震灾害。

For deep mining issue, the combination research method of theoretical analysis, numerical simulation calculation, microseismic monitoring, and field experiments was adopted to research time-space distribution of mining stress field and disaster-pregnant mechanism of mine quake in deep mining. The results showed that the source point accumulating in rear goaf and the front of working face, the latter to be more than the former, the main focus on fracture zone and increase stress area; the source point accumulating in main roof with mining speed, then gradually to the rock strata, after mining it returned to main roof. Mine quake occurred after stationary phase, incubation period and stress （energy） surge phase three stages. Under geological conditions and mining conditions influence, rock stress redistribution, form stress concentrated, and transfer to local area in this process. In local area, stress highly concentrated and deformation energy largely accumulated, under the condition of mining disturbance, deformation energy suddenly release and mine earthquake induced. Shock waves can produce damage when it reach the free surface or some weak area.