深部巷道群高静载低扰动冲击矿压发生机制及防治技术

Mechanism and Prevention Technology of Rock Burst with High Static Load and Low Disturbance in Deep Panel Roadway Group

针对深部巷道群高静载低扰动下突发性冲击矿压的难题,以某煤矿一盘区大巷为工程背景,通过力学分析和数值模拟研究了深部巷道群高静载低扰动诱发冲击矿压的发生机制。结果表明:大巷之间相互影响,导致巷道间煤柱区域应力叠加,高能量积聚在巷道顶底板内;巷道围岩蠕变使得围岩的长期强度降低,引起诱发冲击矿压的临界应力值降低,进而高静载水平下较小的动载扰动即可使叠加应力达到岩体承载极限,在能量达到岩体破坏的最小所需能量时,岩石产生自发性破坏,破坏后巷道围岩系统中的弹性余能转化为动能,造成巷道群冲击矿压发生。根据一盘区巷道群应力和能量分布区域和集中程度,采用大直径钻孔卸压和爆破卸压措施后,降低了应力和能量集中水平,卸压效果明显。

Aiming at the problem of sudden rock burst under high static load and low disturbance in deep roadway,taking a panel roadway of a coal mine as the engineering background,the occurrence mechanism of rock burst induced by high static load and low disturbance in deep roadway group through mechanical analysis and numerical simulation.The results show that the mutual influence between the roadways leads to the superposition of abutment pressure in the coal pillar area between the roadways,and the strong geological tectonic force leads to the accumulation of energy in the roof and floor of the roadways;rock creep reduces the long-term strength of the surrounding rock of the roadways,and reduces the critical stress value of induced rock burst.According to the principle of dynamic and static load superposition,under high static load level,small dynamic load disturbance can cause the superposition stress when the bearing capacity of rock mass reaches the limit and the energy reaches the minimum required energy for rock mass failure,the rock will produce spontaneous failure.After failure,the elastic residual energy in the surrounding rock system of roadway will be converted into kinetic energy,resulting in rock mass impact.According to the stress and energy distribution characteristics of the roadway group in the first panel,after adopting the pressure relief measures of large diameter drilling and blasting,the amount of drilling cuttings is significantly reduced,and the pressure relief effect is good.