亭南煤矿巨厚砂岩含水层顶板灾害协同防控技术及应用

Technology and application of coordinated prevention and control of roof disaster of giant thick sandstone aquifer in Tingnan Coal Mine

针对彬长矿区亭南煤矿主采煤层顶板为典型巨厚砂岩含水层结构,冲击地压、水害、瓦斯为主的多元动力灾害突出问题,基于此现场实测数据分析得到了亭南煤矿“冲击地压-水害、冲击地压-瓦斯”两类典型灾害链,通过室内试验研究了灾害链的致灾机理并制定了灾害协同防控原则,设计了包含采前、采中两阶段以及源头断链整体防控、系统防控隔离断链两种思路的巨厚砂岩含水层顶板灾害协同防控方法,并在亭南煤矿进行了现场应用。结果表明,随冲击幅值增加,动态损伤煤岩体的极限承载能力减小,冲击导致顶板损伤和弱化,沟通巨厚砂岩含水层;强冲击后砂岩试样孔隙率达8.23%,较未冲击增长了34.48%,冲击地压的发生使得岩体裂隙增加,为瓦斯逸散提供了通道;通过巨厚砂岩含水层顶板灾害协同防控技术,实测得到支架平均阻力为35.03 MPa,无明显应力激增现象,工作面涌水稳定于250~280 m^(3)/h,甲烷涌出量在0.2%水平波动。研究结果可为彬长矿区煤矿多元动力灾害防治提供支持,助力实现煤矿灾害风险高效防范,推动多元灾害协同防控技术进步。

The roof of the main coal seam in Tingnan Coal Mine of Binchang Mining Area is a typical thick sandstone aquifer structure,and the multi-dynamic disaster outburst problem of rock burst,water damage and gas.Based on the analysis of the field measured data,two typical disaster chains of'rock burst-water disaster and rock burst-gas disaster'in Tingnan Coal Mine were obtained.The disaster-causing mechanism of the disaster chain was studied through laboratory tests,and the principle of coordinated prevention and control of disasters was formulated.The coordinated prevention and control methods of roof disasters in extremely thick sandstone aquifers were designed,including two stages of pre-mining and mining,as well as the overall prevention and control of source chain breaking and systematic prevention and control of isolated chain breaking,and were applied in Tingnan Coal Mine.The results show that with the increase of impact amplitude,the ultimate bearing capacity of dynamic damaged coal and rock mass decreases,and the impact leads to the damage and weakening of roof,which communicates with the thick sandstone aquifer.The porosity of sandstone samples after strong impact is 8.23%,which is 34.48%higher than that without impact.The occurrence of rock burst increases the fracture of rock mass and provides a channel for gas escape.Through the cooperative prevention and control technology of roof disaster in extremely thick sandstone aquifer,the average resistance of the support is 35.03 MPa,and there is no obvious stress surge.The water inflow of the working face is stable at 250~280 m^(3)/h,and the methane emission fluctuates at the level of 0.2%.The research can provide basic theoretical support for the prevention and control of multi-dynamic disasters in coal mines in Binchang mining area,help to achieve efficient prevention of coal mine disaster risks,and promote the progress of multi-disaster collaborative prevention and control technology.