松散含水层下提高开采上限的研究与实践

Study and Practices on Improvement of Mining Up Limit Under Loose Aquifer

为了解放松散含水层下煤炭资源,缩小防水煤柱,提高开采上限,兖州矿区分别在薄煤层炮采、厚煤层分层综采、整层综放开采、网下综放开采等不同开采方式中进行了提高开采上限的试采,观测研究了第四系下组水位、覆岩破裂高度及其发育规律。结果表明:第四系下组水位逐步降低,富水性逐渐减弱;煤层开采后其覆岩可形成具有一定隔水能力的再生顶板;通过深部开采与浅部开采、厚煤层整层综放开采与重复多层开采比较分析,得到覆岩导水裂缝带高度后者比前者低;厚煤层整层综放开采与网下综放开采其防隔水煤岩柱的保护层厚度可为采高的1.5倍,并给出了厚煤层分层开采、整层综放开采和网下综放开采条件下导水裂缝带发育高度的统计公式。

In order to release the coal resources,reduce the water proof coal pillars and improve the mining up limit under the loose aqui-fer,Yanzhou Coal Mining Group had the trial mining to improve the mining up limit as well as the systematic observation and study on the water table of the low group in the Quaternary System,the overburden strata crack height and development law individually in the thin seam drilling and blasting mining,thick seam slicing fully mechanized coal mining,full seam fully mechanized top coal caving mining,fully mechanized top coal caving mining under the steel mesh roof and other different mining.The results showed that the water table of the low group in the Quaternary System was steadily decreased and the watery of the low group was steadily weakened.After the coal mining operation completed,the overburden strata would form a regenerated roof with certain water isolated capacity.With the comparison analy-sis on the deep mining and shallow mining,the full thick seam fully mechanized top coal caving mining and repeated multi slice mining,the water conducted cracking height in the overburden rock of the late mining method would be lower than the first mining method.The protective layer thickness of the water prevention and isolation coal and rock pillars for the full thick seam fully mechanized top coal caving mining and fully mechanized top coal caving mining under the steel mesh artificial roof could be 1.5 times of the coal cutting height and could provide the static formula of the water conducted cracking development height under the conditions of the thick seam slicing mining,full seam fully mechanized top coal caving mining and fully mechanized top coal caving mining.