柳林矿区4^#煤层底板井下矿压破坏带深度实测研究

Study on Coal No.4 Floor Underground Pressure Fracture Zone Depth Measuring in Liulin Mining Area

河东煤田柳林矿区在水文地质单元上属柳林泉域岩溶地下水系统,西部煤层大部分位于岩溶水位之下,底板最高带压达到5 MPa,带压开采问题突出。为了解煤层在开采过程中底板破坏带的深度,给安全带压开采提供依据,在矿区的北部、中部和南部共选取3个点进行实测研究。综合各测试点不同深度钻孔不同位置注水量的变化曲线分析,初步确定了3个测试点4#煤层采后矿压扰动破坏带深度分别为:邓家庄12.92 m,金家庄11.60 m,柳林13.15 m,平均深度12.56 m。将实测值与经验公式计算值进行对比,发现计算值要比实测值高约60%,说明在本矿区经验公式计算结果偏保守。

The Liulin mining area in Hedong coalfield belongs to Liulin karst spring area groundwater system hydrogeologically. The western part coal seams are mostly under the karst water level, the maximum floor pressure can be 5MPa as high, and thus issues in mining under safe water pressure of aquifer are prominent. To find out floor fracture zone depth during the coal seam mining process,and provide basis for mining under safe water pressure. In the northern, middle and southern parts totally selected 3 points carried out measuring studies. After integrated analysis of water injection quantity variation curves of each point different borehole depths and positions, preliminarily determined 3 measuring points coal No.4 post mining rock pressure fracture zone depths respectively： Dengjiazhuang 12.92 m, Jinjiazhuang 11.60 m and Liulin 13.15 m, average 12.56 m. Comparison of measured data and data from empirical formula has found that the calculated data are higher than measured data about 60%, thus illustrated the result from empirical formula is inclined to conservative in the mining area.