关家崖煤矿重复采动巷道变形特征及控制对策研究

Research on deformation features and control strategies of repeated mining roadways in Guanjiaya Coal Mine

针对重复采动巷道围岩变形严重、无法复用,重复采动巷道在服务期内具有明显的叠加演化特征的问题,以关家崖煤矿13092巷道为研究背景,采用现场实测、数值模拟和理论分析的方法,对重复采动巷道变形的叠加扩展特征和控制对策进行了研究。重复采动巷道变形特征分析结果表明:①一次回采扰动下,重复采动巷道变形呈现分区和非对称破坏特征,可划分为快速变形区、强烈变形区和缓慢变形区;裂纹破坏主要在煤壁帮和煤柱帮,而顶底板较少,表现为巷道两帮显著片帮和内移;煤壁帮与顶板、煤柱帮与底板交汇处变形严重。②二次采动巷道在一次破坏基础上叠加扩展,使得非对称破坏更加显著,形成巷道围岩蝶形叠加塑性破坏区。③重复采动巷道围岩控制的重点时间为一次回采阶段,重点区域为强烈变形区和缓慢变形区的巷道煤柱帮一侧。通过分析采动巷道蝶形变形特征和破坏分区规律,提出了重复采动巷道多层次耦合控制技术,采用浅低压−深高压注浆提高煤柱支撑力,采用锚索补强提高支护体支撑力,实现耦合控制。通过加固前后变形量对比分析验证了多层次耦合控制满足巷道复用要求。

The surrounding rock of the repeated mining roadway is severely deformed and cannot be reused,and the repeated mining roadway has obvious overlapping extension features during the service period.In order to solve the above problems,this study takes the 13092 roadway of Guanjiaya Coal Mine as the research background,and adopts on-site measurement,numerical simulation,and theoretical analysis methods to investigate the overlapping extension features and control measures of repeated mining roadway deformation.The analysis of deformation features of repeated mining roadways shows the following points.①Under a single mining disturbance,the deformation of repeated mining roadways exhibits zoning and asymmetric failure features,which can be divided into rapid deformation zone,strong deformation zone,and slow deformation zone.The crack damage mainly occurs in the coal wall and coal pillar walls,with less damage to the roof and floor,manifested as significant fragmentation and inward movement of the two sides of the roadway.Severe deformation occurs at the intersection of the coal wall and roof,as well as the coal pillar and floor.②The secondary mining roadway expands and overlaps on the basis of the primary damage,making the asymmetric damage more significant and forming a butterfly shaped plastic failure zone in the surrounding rock of the roadway.③The key time for controlling the surrounding rock of the repeated mining roadway is the first mining stage.The key area is the coal pillar side of the roadway in the strong deformation zone and the slow deformation zone.By analyzing the butterfly deformation features and failure zoning rules of mining roadways,a multi-level coupling control technology for repeated mining roadways is proposed.Shallow low pressure-deep high pressure grouting is used to improve the support force of coal pillars.The anchor cables are used to reinforce and improve the support force of support bodies,achieving coupling control.The comparative analysis of deformation before and after reinforcement has verified that multi-level coupling control meets the requirements of roadway reuse.