Vol13 No.7: 1304-1312
【Title】Reasonable selection of yield criteria for quantitative analysis of unsaturated soil slope stability
【Author】LIU Zi-zhen1,2; YAN Zhi-xin2; REN Zhi-hua2,3; QIU Zhan-hong1; DUAN Jian2
【Addresses】1 School of Civil Engineering and Architecture, Taizhou University, Taizhou 318000, China; 2 School of Civil Engineering and Mechanics, Lanzhou University, Lanzhou 730000, China; 3 Yunnan Province Highway Science and Technology Research Institute, Kunming 650051, China
【Citation】Liu ZZ, Yan ZX, Ren ZH, et al. (2016) Reasonable selection of yield criteria for quantitative analysis of unsaturated soil slope stability. Journal of Mountain Science 13(7). DOI:10.1007/s11629-015-3442-9
【Abstract】The yield criterion parameters of the soil material change with different values of the cohesion and the angle of frictionbecause of sustained rainfall infiltration. Based on the Mohr-Coulomb (M-C) and Drucker-Prager (D-P) yield criteria, some reasonable yield criteria selections were discussed for quantitative analysis of unsaturated soil slope stability. Moreover, a critical point was found at the effective angle of friction equaling to 16.5° by transformation of parameters related to unsaturated soil under sustained rainfall. When the effective angle of friction more than 16.5°through parameter transformation of different yield criteria under natural condition, the calculation result of the safety factor was such that: f(DP1) > f(M-C) > f(equivalent M-C) > f(DP2) > f(DP3). While the effective angle of friction less than 16.5° , through parameter transformation, the safety factors were in the following order: f(DP1) > f(M-C) > f(DP2) > f(equivalent M-C) > f(DP3). The calculated results from a case study showed that the equivalent M-C yield criterion should be the best at evaluating soil slope stability before rainfall; the DP2 yield criterion should be selected to calculate the soil slope stability at the effective angle of friction less than 16.5°under sustained rainfall. The yield criterion should be selected or adjusted reasonably to calculate the safety factor of unsaturated soil slopes before and during sustained rainfall.
【Keywords】Unsaturated soil slope; Yield criteria; Parameter transformation; Rainfall; Safety factor