机构地区:[1]中国矿业大学(北京)能源与矿业学院,北京100083 [2]厚煤层绿色智能开采教育部工程研究中心,北京100083 [3]冀中能源峰峰集团有限公司梧桐庄矿,河北邯郸056011 [4]兖矿能源集团股份有限公司山东煤炭科技研究院分公司,山东济南250117 [5]兖矿新疆矿业有限公司硫磺沟煤矿,新疆昌吉831100
出 处:《岩石力学与工程学报》2024年第11期2753-2765,共13页Chinese Journal of Rock Mechanics and Engineering
基 金:国家重点研发计划资助项目(2023YFC2907501,2022YFC2904002);中央高校基本科研业务费专项资金资助(BBJ2024008)。
摘 要:充填开采是减缓采场矿压、岩层运动和地表沉陷程度的有效手段。为指导充填工作面支护参数选择,以古城煤矿1123工作面为工程背景,采用现场实测、室内实验、理论分析研究坚硬顶板厚顶煤充填工作面岩层运动特征,揭示厚顶煤充填工作面支架-围岩耦合作用关系,提出厚顶煤充填工作面支护参数优化方法。结果表明:充填体支撑作用下覆岩采动裂隙最大发育高度位于坚硬顶板下缘,顶板微震事件数量少于底板岩层,最大发育高度30 m。顶板载荷时序曲线以降阻型为主,不存在周期变化特征,表明坚硬顶板呈现连续下沉特征;构建坚硬顶板运动模型,得到“ʅ”形下沉曲线,发现当采空区充实率达到90%,坚硬顶板运动模式由周期断裂转变为连续下沉型;通过单轴和三轴压缩实验,结合CT扫描发现厚顶煤在采空区一侧失去限制后,内部裂隙扩展严重,碎胀系数大,降低了充填效率。提出了厚顶煤充填工作面支架阻力确定方法,从刚度耦合和强度耦合2个方面分析支架-围岩相互作用关系,考虑厚顶煤刚度和强度实现支架参数优化区识别,提出充填工作面支护参数优化原则:将支架阻力曲面划分为高敏感区和低敏感区,提出支架刚度应在高敏感区选择。支架初撑力下限为直接顶及厚顶煤载荷,上限值为厚顶煤残余强度。开展1123工作面支护参数优化工业试验,发现初撑力24 MPa超出支护强度上限,直接导致厚顶煤二次破碎,支架载荷时序曲线全程降阻;初撑力降至10 MPa,载荷时序曲线转变为全程增阻型,控顶区厚顶煤连续下沉,二次破碎和冒顶现象减少,显著提升充填开采效率。Backfilling mining is an effective method to reduce the mining pressure,rock movement and surface subsidence.To guide the selection of support parameters for the backfilling longwall face,taking the 1123 longwall panel of Gucheng coal mine as the background,theoretical analysis,physical simulation and on-site measurement are used to study the characteristics of rock movement under the conditions of backfilling mining with thick top coal and hard roof,to reveal the coupling relationship between the support and the surrounding rock,and to propose the optimization method of support parameters for backfilling face with thick top coal.The results show that the maximum height of mining-induced fractures under the support of backfilling body is located at the lower edge of the hard roof.The number of microseismic events in the roof is less than that in the floor,and the maximum height is 30 m.The roof load time series curve is dominated by the descending resistance type,and there is no periodic variation characteristics,indicating that the hard roof is characterised by continuous settlement.The settlement model of the hard roof is constructed and the settlement curve of“ʅ”shape is obtained.The backfilling rate of the gob reaches 90%,and the movement mode of the hard roof changes from periodic fracture to continuous settlement type.Through uniaxial and triaxial compression experiments,combined with CT scans,it is found that after thick top coals loss restriction of the gob side,the internal fractures expand severely and the crushing coefficient increases,which reduces the backfilling ratio.A method for determining the support resistance in backfilling face is proposed.The interaction relationship between support and surrounding rock is analyzed from two aspects of stiffness coupling and strength coupling.Considering the stiffness and strength of thick top coal,the identification of support parameter optimization area is realized,and the optimization principle of support parameters of backfilling face is proposed.The
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