综采过背斜构造临空巷道冲击地压防治技术研究
Research on technology of preventing mine rock burst of roadways near gob when fully-mechanized over anticlinal structure
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摘要: 为了解决葫芦素煤矿21103工作面过B4背斜区域临空巷道冲击地压问题,采用微震、应力监测及现场实测研究了21103工作面过B4背斜期间回风巷围岩变形破坏特点,结果表明:21103回风巷冲击危险高是由采空区、构造及超前支承压力等因素影响,背斜构造区域煤岩体内积聚了大量弹性能,揭露背斜轴部时单个微震事件释放的能量更大,冲击危险性较揭露背斜两翼也更大。背斜两翼应力集中程度为正常巷道段的1.23倍,背斜轴部应力集中程度为正常巷道段的1.47倍。对21103回风巷设计采用由上至下分阶段四级高强卸压方法,对于监测具有冲击危险区域,采取大直径钻孔或爆破解危措施,降低了21103回风巷冲击危险程度,确保21103工作面过B4背斜期间安全回采。Abstract: In order to solve the problem of rock burst prevention in roadways near gob when passing through the B4 anticline in the No.21103 working face of Hulusu coal mine,the deformation and failure characteristics of surrounding rock in the return airway of No.21103 working face passing B4 anticline were studied using microseismics,stress monitoring and on-site measurements.It is shown that the high impact risk of the No.21103 return airway is affected by factors such as gob,structure and advanced bearing pressure.A large amount of elastic energy has accumulated in the coal-rocks in the anticline structural area.When the anticline is exposed,the energy released by a single microseismic event is greater,and the impact risk is also greater than that of the anticline.The stress concentration of the two wings of anticline is 1.23 times that of the normal roadway section,and the stress concentration of the anticline axis is 1.47 times that of the normal roadway section.For the No.21103 return airway design,the four-stage high-strength pressure-relief method from top to bottom is adopted.For monitoring areas with impact danger,large-diameter drilling or blasting hazard measures are taken to reduce the impact risk of the No.21103 return airway and ensure No.21103 safe mining during working face during crossing B4 anticline.