采空区遗留煤柱下方回采巷道失稳特征及控制技术研究  

Research on instability characteristics and control technology of the mining roadway below the remaining coal pillars in the goaf

作　　者：曹金钟 高乐 闫鹏飞 李猛 陈雷 杨华康 CAO Jinzhong;GAO Le;YAN Pengfei;LI Meng;CHEN Lei;YANG Huakang(Tashan Coal Mine,China Coal Datong Energy Co.,Ltd.,Datong 037001,China;School of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]中煤大同能源有限责任公司塔山煤矿,山西大同037001 [2]北京科技大学土木与资源工程学院,北京100083

出　　处：《工矿自动化》2022年第4期44-52,共9页Journal Of Mine Automation

基　　金：国家自然科学基金项目(52011530037)。

摘　　要：采空区下特厚煤层开采时,上煤层遗留煤柱和相邻工作面回采将对回采巷道的稳定性产生重要影响。目前对回采巷道变形破坏机理及控制的研究未考虑近距离留煤柱开采条件下特厚煤层临空巷道这种复杂环境。针对该问题,以塔山煤矿30503修复巷为工程背景,采用现场监测、理论分析及数值模拟等方法,分析了该巷道的变形破坏机理,提出了相应的巷道围岩支护技术。在30503修复巷顶板布置顶板离层仪,实时监测记录顶板各位置岩层位移情况。监测结果表明:由于受相邻工作面回采的影响,且距上覆遗留煤柱距离较近,30503修复巷顶板内围岩已较为破碎,在巷道掘进后,顶板变形速度快、离层量不断增加且影响范围广。针对监测结果,从遗留煤柱对巷道变形破坏的影响及基本顶断裂位置对巷道变形破坏的影响2个方面进行分析:①巷道的不合理布置是导致修复巷破坏的重要原因,同时为避开遗留煤柱的影响,将巷道布置在距煤柱中心35 m(煤柱边缘25 m)以外的范围。②修复巷掘进位置受遗留煤柱影响严重,巷道掘进前已处于高应力集中区域;当相邻工作面回采后,基本顶破断位置位于修复巷顶板上方,这是导致巷道顶板破碎的直接原因。针对上述分析结果,对不同宽度煤柱偏应力分布演化规律进行数值模拟分析,并提出了针对性的围岩稳定性控制技术方案:①在保证煤柱具有足够的安全性和避免资源浪费前提下,将30503修复巷区段煤柱宽度设为8 m。②近距离特厚煤层临空巷道掘进时,采用水力致裂措施减弱上覆遗留煤柱对煤层的影响。③选用锚网索+喷浆+单体支柱的支护方案对新掘巷道进行联合支护。为验证围岩稳定性控制技术的应用效果,采用十字观测法对30503工作面新修复巷掘进过程中的巷道变形量进行连续监测,结果表明:回采期间两帮变形量为90 mm,顶底板变形量为When the extra thick coal seam is mined in the goaf,the remaining coal pillar of upper coal seam and adjacent working face will have an important impact on the stability of mining roadway.At present,the research on deformation and failure mechanism and control of mining roadway does not consider the complex environment of gob-side roadway in extra thick coal seam under the condition of short distance coal pillar mining.In order to solve the problem,taking the 30503 repaired roadway in Tashan Coal Mine as the engineering background,the deformation and failure mechanism of the roadway is analyzed by using the methods of field monitoring,theoretical analysis and numerical simulation.And the corresponding surrounding rock support technology is proposed.A roof separator is arranged on the roof of 30503 repaired roadway to monitor and record the rock displacement at each position of the roof in real time.The monitoring results show that the surrounding rock in the roof of 30503 repaired roadway has been broken due to the impact of adjacent working face and the short distance to the overlying remaining coal pillar.After the roadway excavation,the roof deformation speed is fast,the seperation volume increases continuously and the impact range is wide.According to the monitoring results,the impact of the remaining coal pillar on the deformation and failure of the roadway and the impact of the fracture position of the basic roof on the deformation and failure of the roadway are analyzed.The results show the following points.①The unreasonable arrangement of the roadway is an important reason for the damage of the repaired roadway.At the same time,in order to avoid the impact of the remaining coal pillar,the roadway is arranged at a distance of more than 35 m from the center of the coal pillar(25 m from the edge of the coal pillar).②The excavation position of repaired roadway is seriously affected by the remaining coal pillar,and the roadway is in the high stress concentration area before excavation.When the adjacent 305

关 键 词：近距离煤层留煤柱开采 特厚煤层临空巷道 修复巷 巷道变形破坏 偏应力 围岩稳定性 水力致裂 

分 类 号：TD322[矿业工程—矿井建设]