孔隙压力-应力耦合下煤岩渗透特性研究

Study on Coal Rock Permeability Characteristics under Pore Pressurestress Coupling

为研究高阶煤在渗流-应力耦合条件下的渗透性及煤岩试样变形破坏过程中的渗透率变化规律,采用MTS816电液伺服岩石试验系统,以围压和孔隙压力为变量进行了煤岩全应力-应变渗透性试验。研究得到了不同试验条件下煤岩的变形与渗透率的关系。试验结果显示,煤岩初始加载阶段围压和孔隙压力直接影响着煤岩渗透率的大小,煤样的峰值渗透率一般出现在应变软化阶段且变化达到1~3个数量级,围压大小影响渗透率的变化幅度。

In order to study the permeability of high-rank coal under the seepage-stress coupling condition and the change law of permeability during the failure of coal and rock samples, the MTS816 electro-hydraulic servo rock test system was used to test the full stress-strain permeability of coal rocks with confining pressure and pore pressure as variables. The relationship between deformation and permeability of coal rock under different test conditions is studied through experiments. The results showed that the initial coal loading stage rock confining pressure and pore pressure directly affects the coal permeability, the permeability of the coal-like peaks generally appear in the softening stage and the change in permeability reaches 1 to 3 orders of magnitude, the size of the permeable confining pressure.