极近距离煤层多采空区下巷道稳定性影响因素及支护对策研究

On influence factors of stability of roadway under many gobs in ultra-close coal seams and supporting countermeasures

针对大同矿区侏罗纪下组可采煤层多、层间距离近的特点,应用数值模拟对极近距离煤层多采空区下巷道稳定性影响因素进行了系统研究,研究结果表明近距离煤层群开采时,上层煤柱宽度越大,巷道越靠近采空区,层间距越大,下层巷道顶板受力越小,越容易维护。对巷道稳定性的影响从大小依次为煤柱下方不同水平位置影响大于层间距影响大于煤柱宽度影响。基于此,提出从巷道布置、支护措施、预爆破上覆煤柱等来解决极近距离煤层多采空区下巷道的稳定问题。

Aiming at the characteristics of many ruinable coal seams and close-distance layers in Lower Jurassic group in Datong mining area, a systemic research is conducted on the influence factors of the stability of the roadway under many gobs in ultra-close coal seams with numerical simulation. The research results show that during the mining of the close-distance coal seam group, when the width of the upper layer coal pillar is greater, and the roadway is closer to the gob, and interlayer spacing is greater, the lower roadway roof stress will be smaller and it will be easier to maintain the roadway. The influence of different level under the coal pillar on the road- way stability is greater than the interlayer spacing, which is greater than the width of coal pillar. Based on this, the paper lists some methods such as roadway layout, support measures, overly- ing coal pillar pre-blasting and so on to solve the stability problem of the roadway under many gobs in ultra-close coal seams.