Vol17 No.10: 2577-2590
【Title】Stability analysis of an unsaturated soil slope considering rainfall infiltration based on the Green-Ampt model
【Author】LIU Zi-zhen1*; YAN Zhi-xin2,3; QIU Zhan-hong1; WANG Xiao-gang1; LI Ji-wei1
【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 School of Civil and Traffic Engineering, Henan University of Urban Construction, Pingdingshan 467000, China
【Corresponding author】LIU Zi-zhen
【Citation】Liu ZZ, Yan ZX, Qiu ZH, et al. (2020) Stability analysis of an unsaturated soil slope considering rainfall infiltration based on the Green-Ampt model. Journal of Mountain Science 17(10). https://doi.org/10.1007/s11629-019-5744-9
【Abstract】Based on the principle of saturated infiltration and the Green-Ampt model, an unsaturated infiltration model for a soil slope surface was established for either constant moisture content, or depth-varying moisture content and the slope. Infiltration parameters in the partially saturated slope were revealed under sustained rainfall. Through analysis of the variation of initial moisture content in the slope, the ponding time, infiltration depth, and infiltration rate were deduced for an unsaturated soil slope subject to rainfall infiltration. There is no ponded water on the surface of the slope under sustained low-intensity rainfall. The results show that the infiltration parameters of an unsaturated slope are influenced by the initial moisture content and the wetting front saturation, the soil cohesion and rainfall intensity under sustained rainfall. More short-term slope failures can occur with the decrease of cohesion of the soil of the slope. The ponding time and infiltration depth differ considering constant or different initial moisture content respectively in the soil slope. Then, best-fit curves of the infiltration rate, ponding time, and infiltration depth to the wetting front saturation were obtained with constant or different initial moisture contents. And the slope failure time is roughly uniform when subject to a rainfall intensity I>5 mm/h.
【Keywords】Rainfall infiltration; Unsaturated infiltration model; Wetting front saturation; Slope safety factor