上遗留边界煤柱影响下巷道应力异常段围岩控制技术研究

Surrounding rock control technology for abnormal stress section of roadway influenced by upper boundary pillar

基于煤层群开采期间上遗留边界煤柱对于底板煤岩体的影响特征为工程背景,通过理论分析、精细化数值模拟分析、工业性试验和矿压监测等研究方法,对上遗留边界煤柱影响下巷道应力异常段围岩控制技术进行研究。结果表明:理论计算得知在遗留边界煤柱中轴线正下方主要受垂直应力影响;而在遗留边界煤柱两侧正下方主要受剪切应力影响;数值模拟运算得知051606回风巷应力异常段顶板主应力差主要集中于遗留边界煤柱中轴线正下方处,顶板剪切应力约为6.0-7.0MPa,底板剪切应力约为5.0-6.0MPa,主要集中于遗留边界煤柱两侧正下方处,理论计算与数值模拟结果相一致;后续051606工作面回采期间巷道应力异常段围岩偏应力分布整体呈非对称形式,针对性采用非对称补强修复措施。矿压监测表明围岩整体变形量控制良好,能够很好的满足安全生产需求。

Based on the engineering background of the influence of upper leftover boundary pillar on floor coal and rock mass during the mining of coal seam group, the surrounding rock control technology of roadway abnormal stress section under the influence of upper left boundary pillar is studied through a series of methods such as theory analysis, refined numerical simulation analysis, field industrial test and ground pressure monitoring. The results show that: the vertical stress mainly affects the zone below the central axis of the leftover boundary coal pillar, and this stress mainly affects the zones below the sides of the boundary coal pillar;the numerical simulation results show that the difference of main stress concentrates at the position below the central axis of the boundary coal pillar. The shear stress of concentrates at the position below the sides of the boundary coal pillar.The distribution of deviatoric stress of surrounding rock in abnormal stress section of roadway during the subsequent mining period of 051606 working face presents an overall asymmetric shape, and asymmetric reinforcement and repair measures are adopted. The ground pressure monitoring shows that the overall deformation of surrounding rock is well controlled.