Experimental Study of the Law of Effective Stress by Methane Pressure

This paper introduced effective stress law under pore methane pressure. Test results prove the effectivestress law is in accord with the revised Terzaghi formula. The equivalent coefficient of pore pressure(a)is a bilinearfunction of volulmetric stress(Θ)and pore pressure(p).Based on the numerical features of a,4 zones were dividedin Θ-p area,i.e. the non-effective zone,normal effective zone,fracturing zone and the equivalent soil zone.