The soil‐water characteristic curve (SWCC) plays an essential role in the analysis of the shear strength, deformation, hydraulic conductivity, and aqueous diffusion of unsaturated soils. A review of methods proposed for fitting the main SWCCs is presented. The methods can be categorized into three groups, namely, (i) empirical methods, (ii) domain methods, and (iii) theoretical methods. A hysteretic model considering the contact angle hysteresis is proposed for fitting the main SWCCs based on a theoretical method. The model links the physical quantities at the micro‐and macro‐scale. Specifically, a modified expression describing the relationship between the volume of the liquid bridge and the water content is derived, and the contact angle hysteresis behavior is modeled based on the study of total thermodynamic potential energy. The model has a clear physical meaning, and the parameters can be obtained easily. Comparisons of the model simulation and experimental data show that the proposed model accurately captures the main features of the SWCC and describes the nonlinear relationship between the matric suction and the water content during wetting and drying processes.

中文翻译：

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考虑接触角滞后的水土特征曲线拟合模型

土水特征曲线（SWCC）在分析非饱和土的抗剪强度，变形，水力传导率和水扩散方面起着至关重要的作用。本文介绍了拟议的主要SWCC拟合方法。这些方法可以分为三类，即（i）经验方法，（ii）领域方法和（iii）理论方法。提出了一种基于接触角滞后的滞回模型，用于基于理论方法拟合主SWCC。该模型链接了微观和宏观尺度上的物理量。具体地，导出描述液桥的体积和水含量之间的关系的修改表达式，并且基于对总热力学势能的研究，对接触角滞后行为进行建模。该模型具有明确的物理含义，并且可以轻松获得参数。模型仿真和实验数据的比较表明，所提出的模型准确地捕捉了SWCC的主要特征，并描述了在润湿和干燥过程中基质吸力与含水量之间的非线性关系。