煤矿安全2019，Vol.50Issue(9)：197-202,6.DOI:10.13347/j.cnki.mkaq.2019.09.048
上保护层开采下伏煤岩体应力卸压规律力学分析
Mechanical Analysis on Pressure Relief Principle of Underlying Coal-rock Mass with Upper Protective Seam Mining Method
摘要
Abstract
On the foundation of analyzing two functions of mining protective seam, namely, relieving pressure and preventing coal and gas outburst, the mechanical model of underlying coal-rock mass was developed according to elastic force theory. In addition, the stress of any point at floor is deduced. The failure evaluation criterion of underlying coal-rock mass is also proposed. Combining the specific engineering parameters of Pingdingshan No.12 coal mine, the relation between the depth of the mining-induced fractured zone in floor and mining height has been proposed using theoretical analysis. Fracture development and stress relief law of outburst coal seam under different mining height of upper protective layer are analyzed. The studies indicate that with the increase of the depth of floor, the underlying coal-rock mass will only relieve a certain pressure and the pressure relief protection range will also narrow. Besides, the stress distribution will also develop to"V"shape form"U"shape. When the height of protective seam is designed as 2.0 m, the stress relief ratio will rise to 90% which can ensure the pressure-relief effect as well as benefit the economic and social benefits. The engineering application shows that after mining the upper protective seam of Ji-14, the gas pressure of Ji-15 outburst coal seam decreased from 1.78 MPa to 0.35 MPa with a drop of 81%, which is consistent with the theoretical calculation results of stress relief.关键词
上保护层/卸压开采/卸压规律/力学分析/煤与瓦斯突出Key words
upper protective seam/pressure relief mining/principle of pressure relief/mechanical analysis/coal and gas outburst分类
矿业与冶金引用本文复制引用
殷伟,高焱,陈家瑞,姚振峰,吕春欣..上保护层开采下伏煤岩体应力卸压规律力学分析[J].煤矿安全,2019,50(9):197-202,6.基金项目
淮安市自然科学基金资助项目(HAB201708) （HAB201708）
