Represention of anisotropy in unsaturated permeabilities for soils based on pore connectivity-tortuosity parameter
ZHANG Zhao1, LIU Feng-yin1, QI Ji-lin1, 2, CHAI Jun-rui3, 4, WANG Shuang1, LI Hui-yang5, GAO Yong-bao6
1. Institute of Geotechnical Engineering, Xi'an University of Technology, Xi'an 710048, China; 2. College of Civil and Transportation Engineering, Beijing University of Civil Engineering and Architecture, Beijing 100044, China; 3. State Key Laboratory Base of Eco-hydraulics in Northwest Arid Region of China (Xi'an University of Technology), Xi'an 710048, China; 4. College of Hydraulic and Environmental Engineering, China Three Gorges University, Yichang 443002, China; 5. Sinohydro Foundation Engineering Co., Ltd., Tianjin 301700, China; 6. CCCC First Highway Consultants Co., Ltd., Xi'an 710065, China
Abstract：Accurate characterization of the anisotropy in unsaturated permeability for soils is significant in simulating flow and contaminant transport. Based on the Mualem’s unsaturated permeability function, the power type expression for the relationship between the anisotropy coefficient and the effective degree of saturation is derived by introducing the pore connectivity-tortuosity parameter so as to describe the nine types of the anisotropy in unsaturated permeability. In the process of anisotropy coefficients varying with the effective degree of saturation, there exists a critical point at which the dominance of flow direction switches. This expression is then validated using the numerical test results of unsaturated permeability of a pore network for modeling the soil samples in the previous literatures. Combining with the Van Genuchten-Mualem function, this expression can be finally used to represent the effect of matric suction on the anisotropy in permeability for four soils in the existing literatures.
张昭, 刘奉银, 齐吉琳, 柴军瑞, 王爽, 李会勇, 高永宝. 基于孔隙连通-迂曲参数表征土的非饱和渗透各向异性[J]. 岩土工程学报, 2018, 40(S1): 147-152.
ZHANG Zhao, LIU Feng-yin, QI Ji-lin, CHAI Jun-rui, WANG Shuang, LI Hui-yang, GAO Yong-bao. Represention of anisotropy in unsaturated permeabilities for soils based on pore connectivity-tortuosity parameter. Chinese J. Geot. Eng., 2018, 40(S1): 147-152.
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