Aiming at the difficulty in field measurement of roof mining failure zone after mining, in order to master the height of fractured zone in roof strata caused by underground mining and ensure safe mining above water - bearing stratum. In this paper, the method of the empirical formula prediction and FLAC3D numerical simulation was adopted to study the height of roof mining fractured zone in Yangcheng Coal Mine, then the system of double ends borehole plugging device in measuring leakage was applied to verify the results of the formula and simulation, and the three results were compared with each other. The research shows that: the estimated height of coal roof mining failure zone of theoretical formula is 41. 3m, the result of numerical simulation is 33. 92m, and the result of field measurement is 37. 67m. The simulation result is basically close to field measurement, while the result of empirical formula is conservative. After comprehensive consideration, the roof strata maximum fractured failure height of the working face is 37. 67m. With the working face advancement, plastic zone of the roof strata is still increasing. When the working face reaches 90m, development height of the roof strata fracture reaches the maximum value of 33. 92m, and the height no longer increases. Its shape is a straight line which is approximately parallel to the top of coal seam, and the change trend of the roof plastic zone is consistent with that of the maximum principal stress. From the section of coal seam tendency, the shape of the roof plastic zone is approximate to the saddle shape, which is consistent with the actual situation.%针对工作面开采后顶板采动破坏带探测难题,为了掌握开采引起的顶板岩层裂隙发育高度,确保含水层下煤层安全开采,先采用经验公式预计、FLAC3D数值模拟等方法,对阳城煤矿实际工作面顶板采动裂隙发育高度进行计算和模拟,再运用"钻孔双端封堵测漏装置"进行现场实测,对经验公式预计和数值模拟结果进行验证,并使三者结果进行相互比对.研究表明:①顶板采动破坏带发育高度的理论公式预计值为41.3m,数值模拟结果为33.92m,现场实测结果为37.67 m;数值模拟结果与现场实测所得结果基本接近,而经验公式预计的结果偏于保守,综合考虑,确定该工作面顶板岩体采动最大破坏高度为37.67 m;②随着工作面推进,顶板塑性区不断增大,当工作面推进至90m时,顶板岩体裂隙发育高度已经达至上限值33.92m,此后不再增加,塑性区最大高度呈一条与煤层顶部近似平行的直线,且顶板塑性区变化与最大主应力的变化趋势一致;③从煤层倾向切面来看,顶板塑性区发育高度形状近似成"马鞍形",这与实际相吻合.综上所述,该煤矿顶板采动破坏高度模拟与实测结果,可指导煤矿安全生产,并为矿井防治水提供重要的科学依据,具有重要的实用价值.
展开▼
