Study on Strength Reduction Method with Two Reduction-Factors

Because development degree and order as well as decay rate and degree of shear strength indexes, cohesion C and angle of internal friction , are not equal as slope failure, both should have their own security reserve. For this reason, it was proposed that C and  should have different reduction-factors, rather than same about strength reduction method (SRM). And to take a slope as an example, by FLAC SRM and strength reduction slice method (SRSM), reduction-factors of the two indexes and dangerous slide surfaces of the slope were computed and comparatively analyzed under 9 different reduction conditions. The results obtained by FLAC SRM and SRSM accorded with each other well. Therefore conclusions can be drawn that different reduction conditions correspond to different two reduction-factors and dangerous slide surfaces, so that all these dangerous slide surfaces form a dangerous slide region; single reduction-factor method that reduction-factors of C and  are same is only a special case of two reduction-factors method; two reduction-factors method can just reasonably reflect respective roles of C and  as slope instability. The conclusions in turn confirm the above-mentioned viewpoint again.