近距离煤层群上行开采覆岩垮落及运移规律研究

Study on overlying strata caving and movement regularity of ascending mining in contiguous seams

为研究近距离煤层群上行开采覆岩垮落及运移规律,以晋城某矿近距离煤层群为研究背景,结合其煤层地质条件建立二维相似模拟试验模型,对煤层群开采过程中覆岩垮落和运移规律进行了监测。试验结果表明:煤层群上行开采过程中,上煤层周期来压步距小于下煤层,且覆岩离层高度更大;上煤层表现为工作面的大小周期来压现象,伴随着大周期来压剧烈和小周期来压不明显,且基本表现为小周期来压时垮落角减小,大周期来压时垮落角增大的规律;上煤层开采后覆岩破碎难以形成结构,其覆岩离层高度增加幅度较小。研究结论可为类似条件上行开采和岩层控制提供参考。

In order to study the overlying strata caving and movement regularity of ascending mining in contiguous seams,according to the specific engineering geologic conditions of contiguous seam group for a mine in Jincheng city,a two-dimensional physical simulation model was built. The overlying strata caving and movement were monitored during the excavation of coal seam group.The results showed that during the full process of the ascending mining,the upper coal seam has shorter periodic weighting length and larger height of bed separation than the lower coal seam; the upper coal seam had large and short periodic weighting length,and showed the phenomenon of serious and mild periodic weighting respectively,the face caving angle decreased during the small periodic weighting period and increased during the large periodic weighting period; after the excavation of the upper coal seam,the overlying strata was hard to form stable structure and the increase rate of the bed separation was small. The results could provide the reference for the ascending mining and ground control in the similar coal seam.