厚硬基本顶综放沿空巷道覆岩应力分布特征及合理煤柱宽度确定  

Characteristics of overburden stress distribution and rational pillar width determination of gob-side roadway with thick and hard basic roof in fully mechanized top coal caving workface

作　　者：蒋威[1,2,3] 鞠文君 汪占领[2,3] 张镇[2,3] 石蒙[2,3] JIANG Wei;JU Wenjun;WANG Zhanling;ZHANG Zhen;SHI Meng(School of Energy and Mining,China University of Mining and Technology-Beijing,Beijing 100083,China;Coal Mining Branch,China Coal Research Institute,Beijing 100013,China;Coal Mining&Designing Department,Tiandi Science&Technology Co Ltd,Beijing 100013,China)

机构地区：[1]中国矿业大学(北京)能源与矿业学院,北京100083 [2]煤炭科学研究总院开采研究分院,北京100013 [3]天地科技股份有限公司开采设计事业部,北京100013

出　　处：《采矿与安全工程学报》2020年第6期1142-1151,共10页Journal of Mining & Safety Engineering

基　　金：国家自然科学基金项目(51774186)。

摘　　要：合理选择护巷煤柱宽度是综放沿空掘巷技术成功应用的关键。以柳巷煤矿工程地质条件为背景,基于弹性地基梁理论、内外应力场理论计算分析沿空巷道覆岩结构特征及其内应力场分布,使用离散元模拟软件建立多组数值模型,分析不同煤柱宽度与应力集中系数下巷道围岩变形特征,系统研究掘采过程中覆岩结构与煤柱宽度对巷道受载变形机制的影响。定义煤柱护巷系数ψi,以此对数值模拟结果进行综合评价,确定合理煤柱宽度。研究结果表明:1)随着悬顶长度增加,基本顶岩梁最大弯矩增大,岩梁破断位置与采空区煤壁间距减小。2)厚硬基本顶综放工作面因基本顶厚度大、来压步距大及开采强度高等因素致使其内应力场范围较常规工作面更大。结合现场工程地质数据,确定内应力场范围14.67~17.33 m。3)基于覆岩结构分析确定试验工作面合理煤柱宽度范围为5~10 m,采用数值模拟进一步研究表明,以7 m为分界,随着煤柱宽度增加,煤柱稳定性与覆岩结构先后主导巷道受载变形机制。4)通过综合评价确定合理煤柱宽度为7 m,应用效果通过现场监测得到验证。The rational selection of coal pillar width is the key to the successful application of gob-side entry driving technology in fully mechanized top-coal caving.With the engineering geological conditions of Liuxiang Coalmine as research background,based on elastic foundation beam theory and internal,external stress field theory,overburden structure and the distribution range of internal stress field has been calculated and analyzed.Several numerical models have been established with discrete ele ment simulation software to analyze the deformation characteristics of roadway surrounding rock in the conditions of different pillar widths and different stress concentration factors.And the influence of overburden structure and pillar width on the loading and deformation mechanism of roadway during the excavation and mining process has been studied systematically.Finally,the pillar protection capacity coefficientψi has been defined to evaluate the numerical simulation results comprehensively and determine the reasonable pillar width.Results have shown that:1)With the increase of suspended roof length,the maximum bending moment of the basic roof rock beam increases,while the distance between the rock beam broken position and the coal wall decreases;2)Internal stress field of the fully mechanized caving face with thick and hard basic roof is larger than that of the traditional face because of the larger thickness of the basic roof,larger weighting step and higher mining intensity.Combined with the field engineering geological data,internal stress field of the test face is determined to be 14.67-17.33 m;3)Based on the overburden structure analysis,reasonable coal pillar width in test face is determined to be 5-10 m.Numerical simulation results further show that demarcated by 7 m,with the increase of the coal pillar width,the stability of coal pillar and the overburden structure dominate the loading and deformation mechanism of the roadway successively;4)Through comprehensive evaluation,7 m is determined to be the coal pillar

关 键 词：沿空巷道 煤柱宽度 覆岩结构 煤柱护巷系数 数值模拟 

分 类 号：TD35[矿业工程—矿井建设]