基于层状岩体渗流失稳条件的煤矿突水机理

Mechanism of Water Inrush Based on the Instability of the Seepage Flow in Rock Strata

利用分离变量法进行了层状岩体Forcheimer型非Darcy渗流系统的稳定性分析,从非线性动力学系统结构失稳的视角揭示了煤矿突水的机理.研究表明:矿井突水是由岩层的厚度、渗透特性、渗流液体的力学性质及边界压力共同决定的;当渗流系统的控制参量与边界压力满足一定的条件时,此系统失去稳定性,并引发突水灾害;当某岩层的渗透率比其他岩层低一个量级,而非Darcy流β因子比其他岩层高两个量级时,该岩层为渗流系统的关键层,其渗透特性对系统的稳定性起支配作用.

The structural stability of the Forcheimer's non-Darcy flow in rock strata was analyzed using variables segregating method, and the mechanism of water inrush in coal mines was investigated based on the structural instability of non-linear dynamic seepage system. The results show that water inrush is controlled by the height and seepage properties of every stratum, and the physic properties of the fluid, and the boundary pressures. When both the control parameters and the boundary pressures are content with a certain relation, the system will be unstable, and water inrush may take place. When the permeability of a stratum is less than that of the other strata by one order of amount, and the non-Darcy flow factor β of the stratum is greater than that of the others by two orders of amount, the stratum is a key stratum, the seepage properties of which play a dominant rule in the stability of the system.