The Experimental Approach to Effective Stress Law of Coal Mass by Effect of Methane

摘要: Effective stress law of all kinds coal samples, including steam coal, fat corking thin and anthracite, under pore pressure gas, is experimentally studied using a newly developed test machine. These samples are taken from Coal Mines in Wuda, Hebi, Yanzhou, Yangquan, Qingshui, Gujiao China. The experiment results show that, the tested comply with Biot’s effective law, $${\sigma '}_{ij} = {\sigma}_{ij} - {\alpha}p{\delta}_{ij}$$ where coefficient α not constant, bilinear function volumetric (Θ) (p), that is, $$\alpha a_1 + a_2 \Theta a_3 p a_4 p$$ We define four areas according to numerical feature α, is, functionless area pressure, normal area, fracturing quasi-soil area. mass introduced by this paper constitutive equation study coupled solid fluid. This has significance drainage outburst methane seam.