基于应用“以岩层运动和支承压力分布”为核心的矿山压力控制理论,建立了采场结构力学模型和留巷结构力学模型,阐述了垮落带厚度确定方法,推导了煤矸石压缩前后变形量求解公式,分析了采空区煤矸石压缩和留设巷道围岩变形压缩作用力的来源;利用自制的煤矸石压密试验设备和MTS 815.03电液伺服万能试验机对3种粒径等级(10—20mm、20—30mm、30—60mm)煤矸石的压缩特性进行了系统性研究,得到了煤矸石在不同单轴压缩条件下的碎胀特性、碎胀系数与应力关系曲线,以及压缩过程中的时间相关特性。研究结果表明,采空区煤矸石压缩作用力主要来源于采场裂断拱内岩层重量;煤矸石压缩至密实状态变形量大约为0.3mZ;煤矸石压缩曲线符合对数函数关系;试验结果与现场数据基本吻合。
关键词:
岩层; 运动; 煤矸石; 压缩; 时间效应
Based on the ground pressure and strata control theory with "the strata movement and abutment pressure" as the core, the stope structural mechanical model and the gob-side retaining entry mechanical model are built, the caving zone height is determined, the non-compressed and compressed gangue deformation calculation formula is obtained, the compression effect of coal gangue in the mined-out area is explained and the gob-side retaining entry surrounding deformation is analyzed. For the coal gangue with three kinds of size ranks(10—20mm, 20—30mm, 30—60mm), their compression characteristics are analyzed by MTS 815.03 electron hydraulic servo machine and home-made compression testing-equipment, and its compression-time characteristics are obtained. The results show that the strata weight of the fracture-arch in the stope is the main source of the compression effect of the coal gangue in the mined-out area. The coal gangue deformation is about from beginning to the dense condition; the coal gangue compression curve assumes a logarithmic relationship; the test results agree well with the field data.