Quantitative analysis on double reduction method

Double reduction method (DRM) adopts reduction strategy which utilizes the different reduction coefficients of strength on the cohesion and internal friction angle and this view is more rational. However, the research on double reduction method still lacks of quantitative analysis or reasonable explanation. In the coordinate system of strength parameters, definition of FOS, path of reduction, and critical state are used to analyze the difference between traditional strength reduction method (SRM) and DRM. There is unity in path of reduction with these two methods; DRM can be regarded as the SRM where it begins at an initial virtual strength point to reduce. The gradual process of slope destruction is the attenuation of strength parameters. In this process, c and tan [phi] follow direct proportion function. At the same time, in the coordinate system of strength parameters, the concept of strength reserve can be reflected as the gradual process which is initial strength area approaches to critical strength area