倾斜长壁工作面综放开采覆岩“两带”发育高度研究

Study on Development Height of Overlying Rock"Two Zones"in Fully Mechanized Caving Mining of Inclined Longwall Working Face

以淮北某矿倾斜长壁综放开采工作面为研究对象,在分析覆岩岩性特征的基础上,采用经验公式估算、数值模拟及深基点位移法对覆岩采动裂隙的发育高度进行研究。结果表明:基于关键层理论导水裂隙带高度预测方法、FLAC^(3D)数值模拟与深基点位移监测结果基本一致,而经验公式仅考虑采厚、岩性2种因素影响,预测"两带"发育高度存在一定的局限性,839工作面开采后,冒落带发育高度23.12~27.24 m,裂隙带发育高度91.88~102.08 m,裂采比为14.4~16.0。研究结果为839工作面瓦斯抽采设计、露头防(隔)水煤岩柱留设提供科学依据。

Taking the working face of the inclined longwall fully mechanized caving of a mine in Huaibei as the research object,based on the lithologic characteristics of overlying rocks,the development height of mining-induced fractures in overlying rocks was studied by using empirical formula estimation,numerical simulation and deep base point displacement method.The results showed that the height prediction method of water-conducting fractured zone on the key layer theory,FLAC^(3D) numerical simulation and the monitoring results of deep base point displacement were basically consistent.However,the influence of mining thickness and lithology was only considered in the empirical formula,so there were certain limitations in predicting the development height of"two zones".After mining at 839 working face,the development height of caving zone was between 23.12 and 27.24 m.The height of fracture zone was between 91.88 and 102.08 m,and the ratio of fracture to production was between 14.4 and 16.0.The research results would provide scientific basis for gas extraction design and outcrop water-proof coal-rock pillar setting of 839 working face.