王家岭煤矿综放开采覆岩应力场形成及演化特征

Formation and Evolution Characteristics of Overburden Stress Field in Comprehensive Mining of Wangjialing Coal Mine

为探究综放开采覆岩运动及采动应力动态演化规律,以王家岭煤矿121309工作面为工程背景,采用相似材料模拟及FLAC^(3D)数值模拟软件,分析了不同推进距离下工作面覆岩的应力分布特征、采动应力演化特征、覆岩运移特征及覆岩垮落特征。结果表明,当工作面开切眼完成时,回采工作面覆岩应力变化较小,应力集中程度呈现稳定趋势。当工作面的开采距离增加,工作面覆岩的应力恢复能力逐渐增强,直至覆岩的最大主应力大于最小主应力的恢复程度,当开采距离推进至650m时,应力达到峰值,且王家岭煤矿的黄土沟壑地貌对采煤121309工作面覆岩的应力、变形、位移均有明显的影响,同样对工作面超前支承压力集中程度也有较大影响。

In order to investigate the dynamic evolution law of overburden rock movement and mining stress in integrated mining,taking 121309 working face of Wangjialing coal mine as the engineering background,similar material simulation and FLAC^(3D) numerical simulation soft-ware were used to analyze the stress distribution characteristics of the overburden rock of the working face under different advancing distances,min-ing stress evolution characteristics,overburden rock transport characteristics and overburden rock collapse characteristics.The results show that when the working face opening and cutting eyes are completed,the stress change of the overburden rock of the mining face is small,and the degree of stress concentration shows a stable trend.When the mining distance of the working face increases,the stress recovery ability of the overburden rock of the working face gradually increases,until the maximum principal stress of the overburden rock is greater than the recovery degree of the minimum prin-cipal stress,and the stress reaches the peak when the mining distance is pushed forward to 650 m,and the loess gully topography of the Wangjialing Coal Mine has an obvious influence on the stress,deformation and displacement of the overburden rock of the 121309 working face of the coal min-ing,which also has a greater influence on the overburden bearing pressure of the working face.The degree of concentration also has a large influence.