深部条带开采覆岩“三带”探测及量化评判

Exploration and quantitative evaluation of overburden strata“three zones”in deep strip mining

为研究深部条带开采覆岩裂隙发育高度这一采空塌陷区治理中的关键技术问题,综合运用工程地质钻探、钻孔电视与煤田测井3种方法对济宁煤田某煤矿覆岩采动裂隙进行探测与分析。结果表明:缓倾斜(煤层平均倾角6°)、深埋(平均埋深538 m)、采留比1∶2(采50 m留100 m)的条带式采动下,覆岩“三带”特征显著,空间整体呈“波浪式”破坏形态,地下采空区无明显空洞;垮落带发育高度为8.45 m,为采高的3.0倍,断裂带发育高度为57.55 m,为采高的20.6倍;覆岩“三带”发育高度判别的8个量化指标中,钻孔电视法比工程地质钻探法、煤田测井法精确度高。探测结果较为准确可靠,为深部条带采空塌陷区治理方案的选择提供依据。

In order to study the height of overburden fractures in deep strip mining,engineering geological drilling,borehole television and coalfield well logging have been applied to detect and analyze the overburden fractures in a coal mine in Jining coalfield.The results indicate that,under the strip mining with gentle dip(6°),deep depth(538 m)and 1:2 mining-retention ratio(mining–50 m and remaining–100 m),the“three zones”develop prominently,presenting“wavy”destruction in space,and the goaf has no obvious cavity.The height of caving zone is 8.45 m which is 3.0 times of the mining height,and the fault zone is 57.55 m,20.6 times of the mining height.Among the eight quantitative indicators for judging the development height of“three zones”,borehole television is more accurate than the other two methods.The results of detection are more accurate and reliable,which can provide a basis for the selection of management plan in deep strip mining subsidence area.