韩家湾煤矿浅埋近距离煤层群覆岩破坏规律研究

Failure law of overburden under shallow contiguous coal seams in Hanjiawan Coal Mine

为研究浅埋深、近距离煤层群条件下的覆岩破坏规律,以韩家湾煤矿214201工作面为背景,开展了覆岩地面钻孔、漏失量观测法实测、相似材料模拟研究工作。经对实测数据整理,分析了该地质采矿条件下的覆岩破坏特征,覆岩"两带"发育高度、岩层破断角等。实测得到仅采3^(-1)煤非充分采动的垮采比为6.5、仅采4^(-2)煤垮采比为7.3;相似材料模拟顺序开采2^(-2)煤垮采比为6.0,3^(-1)煤垮采比为6.8,4^(-2)煤垮采比为5.8;2^(-2)煤岩层破断角为59.5°~69°,3^(-1)煤岩层破断角为66°~71°,4^(-2)煤岩层破断角为57°~68°;2^(-2)煤初次来压步距45m,周期来压步距为11~17m;4^(-2)煤初次来压步距为63m,周期来压步距为13~21m。研究表明:韩家湾煤矿浅埋深、近距离煤层群开采条件下,上覆岩层只发育有"两带",下部煤层垮采比降低、上煤层垮采比升高,下部岩层破断角降低、周期来压步距增大的特征。

In order to study the law of overburden failure under the shallow contiguous coal seams,214201 working face of Hanjiawan Coal Mine was taken as the background,the methods of“ground drilling+leakage observation”and similar material simulation for overlying rocks ware carried out.By sorting out the measured data,the failure characteristics of overburden,development height of“two zones”of overburden and breaking angle of strata are analyzed.The measured results show that caving-mining ratio is 6.5 for only 3^(-1) coal with insufficient mining,and 7.3 for only 4^(-2) coal.Similar material simulation show that caving-mining ratio is 6.0 for 2^(-2) coal,6.8 for 3^(-1) coal,and 5.8 for only 4^(-2) coal.Fracture angle of rock formation of 2^(-2) coal strata is 59.5°~69°,that of 3^(-1) coal strata is 66°~71°and that of 4^(-2) coal strata is 57°~68°.For 2^(-2) coal,the initial weighting interval is 45 m,and the periodic weighting interval is 11~17 m.For 4^(-2) coal,the initial weighting interval is 63 m,and the periodic weighting interval is 13~21 m.Research shows that under the shallow contiguous coal seams in Hanjiawan Coal Mine,only“two zones”are developed in the overlying strata,and the caving-mining ratio of the lower coal seam decreases,while the caving-mining ratio of the upper coal seam increases;and the fracture angle of rock formation in the lower rock strata decreases,while the periodic weighting interval increases.