煤层群下行开采底板应力演化规律与合理巷道错距研究  

Study on the evolution law of bottom plate stress and reasonable roadway misalignment in downstream mining of coal seam group

作　　者：丁自伟[1] 巩欣伟 张杰[2] 李宇龙[2] 蔡敏博 姬东 康萌 DING Ziwei;GONG Xinwei;ZHANG Jie;LI Yulong;CAI Minbo;JI Dong;KANG Meng(College of Energy Science and Engineering,Xi’an University of Science and Technology,Xi’an 710054,China;Shaanxi Shanmei Hancheng Mining Co.,Ltd.,Hancheng 715400,China)

机构地区：[1]西安科技大学能源学院,陕西西安710054 [2]陕西陕煤韩城矿业有限公司,陕西韩城715400

出　　处：《西安科技大学学报》2024年第2期213-225,共13页Journal of Xi’an University of Science and Technology

基　　金：国家自然科学基金项目(52074209)。

摘　　要：为解决近距离煤层开采遗留煤柱下伏回采巷道合理布置工程问题,采用理论分析、数值模拟和现场实测相结合的方法,基于半无限平面体理论建立遗留煤柱底板岩层应力分布力学模型,系统研究了遗留煤柱下伏底板岩层应力分布特征及减压区相对位置关系,提出遗留煤柱非均布载荷影响的底板水平/垂向距离判别方法,揭示了遗留煤柱水平/垂向间距对下伏煤层回采巷道应力变化率的影响程度。结果表明:垂直应力集中是导致下伏巷道失稳的主控因素,以垂直应力变化量0.2γH作为评判应力影响程度的临界指标,探究了不同因素影响下的应力扰动程度,随着遗留煤柱尺寸、煤层间距、埋深与岩层垮落角逐渐减小,底板岩层应力影响深度呈递减趋势;随着水平错距增大,巷道围岩垂直应力值、应力变化率差值不断减小,界定两者数值低于0.2γH与0.01时,围岩达到可控稳定状态;现场试验21320回风巷采用外错式25 m进行实测验证,优化布置后巷道顶板相对位移量控制在45 mm以内,服务期间巷道围岩工况稳定,验证了所得安全错距的合理性。In order to solve the problem of reasonable arrangement of the roadway under the residual coal pillar in close distance coal seam mining,the mechanical model of stress distribution of rock layer under the residual coal pillar was established based on the semi-infinite planar body theory by theoretical analysis,numerical simulation and on-site measurement,and the stress distribution of bottom plate rock layer under the residual coal pillar and the relative position of decompression zone were systematically studied,so as to put forward a method of determining the bottom plate horizontal/vertical distance under the influence of uneven load,revealing the influence of horizontal/vertical spacing on the rate of stress change of the residual pillar.The results show that the vertical stress concentration is the main control factor leading to the instability of the downfall roadway,and the vertical stress change of 0.2γH is used as the critical index for judging the degree of stress influence,and the degree of stress perturbation under the influence of different mining factors is investigated,and with the gradual decrease in the size of residual coal pillar,spacing of the coal seams,and the depth of burial and the angle of rock collapse,the depth of stress influence on bottom plate rock layer shows a decreasing tendency;and with the increase of the horizontal misalignment distance,the vertical stress value,stress value and stress value of the surrounding rock are decreased,and with the increase of the horizontal misalignment distance,the depth of stress influence is increased.With the increase of horizontal misalignment,the vertical stress value of the surrounding rock and the difference of stress change rate decreases,and the surrounding rock reaches a controllable and stable state when defining the two values lower than 0.2γH and 0.01;the field test 21320 backwind lane adopts external misalignment of 25 m for the measurement verification,and the relative displacement of the roof plate after the optimization arrangemen

关 键 词：近距离煤层 遗留煤柱 非均布载荷 集中应力 应力变化率 合理巷道错距 

分 类 号：TD322[矿业工程—矿井建设]