断层煤柱及倾角对采动应力及能量分布的影响特征

Effects characteristics of fault pillar and its dip angle on mining-induced stress and energy distribution

针对工作面沿正断层走向布置,建立上下盘工作面开采三维数值计算模型,模拟研究上、下盘工作面采动应力及弹性能的分布特征、断层煤柱宽度及倾角对应力场和能量场的影响规律。研究表明:正断层上盘或下盘工作面开采,断层侧工作面端头及断层煤柱上的采动应力和弹性能较高,且上盘工作面开采时更高,断层阻隔效应较为明显。随着断层煤柱宽度减小,断层对工作面采动应力及弹性能积聚的影响程度逐渐增加,断层侧工作面端头采动应力及弹性能峰值明显升高;当断层煤柱宽度由50 m减小到20 m,断层煤柱应力及弹性能不断升高,煤柱宽度减小为10m时,小煤柱承载能力及弹性能降低。随着断层倾角增大,断层侧工作面及断层煤柱采动应力及能量峰值升高,高角度断层的影响较大。断层侧巷道两帮处于采动高应力状态,积聚着较高的弹性能,回采过程中应加强巷道支护,采取必要的灾害防治措施。

Based on a case that the of working face along the fault strike, a three-dimensional numerical model incorporating mining operations in both hanging wall and footwall is established, where the mining-induced stress and elastic energy distribution characteristics in hanging wall, footwall and the influence of fault pillar width on stress and energy field is studied by numerical simulations. Research shows that： during hanging wall or footwall mining, the high stress and elastic energy occur at the end of fault-side working face and fault pillar. Both stress and energy are higher during hanging wall mining and the fault present significant barrier effect. With decreasing the fault pillar width, the influence of fault on the stress and elastic energy accumulation of the working face gradually increases. The peakvalue of mining stress and elastic energy at the end of fault-side working face significantly increases.When the width of the fault pillar reduces from 50 m to 20 m, the stress and elastic energy of pillar increases, when the pillar width reduces to 10 m, the bearing capacity and elastic energy of small coal pillar reduces. With the increase of the fault dip angle, stress and elastic energy of the end of fault-side working face and pillar increases, fault with a high dip angle will have dramatic influence. Two ribs of the fault-side roadway is in a state of high stress and energy, hence support reinforcement should be adopted during mining process for disaster control.