Abstract It is known that the soil-water characteristic curve (SWCC) of unsaturated soils is hysteretic. The engineering properties of unsaturated soils during the drying process are different from those during the wetting process, and the difference can be related to the hysteresis of the SWCC. Therefore, understanding the hysteresis of the SWCC is crucial in engineering practices. In this paper, both the “rain-drop” and “ink-bottle” effects on the hysteresis of the SWCC are quantified with mathematical equations. In the proposed equations, it is assumed that soil volume changes during the drying and wetting processes are negligible, which is a reasonable assumption for most sandy soils. Based on the proposed theory, the wetting scanning curves were estimated from the main drying curves. The results from the method proposed in this paper have been compared with experimental data from the published literature. Satisfactory agreements were found between the measured and estimated wetting scanning curves. Consequently, the method for estimating the wetting scanning curves from the fitting parameters of the SWCC by using the equations proposed in this paper is recommended.

中文翻译：

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砂土润湿扫描曲线的估计

摘要 众所周知，非饱和土的土水特征曲线（SWCC）是滞后的。非饱和土在干燥过程中的工程性质与润湿过程中的不同，差异可能与SWCC的滞后有关。因此，了解 SWCC 的滞后现象在工程实践中至关重要。在本文中，“雨滴”和“墨水瓶”对 SWCC 滞后的影响都用数学方程量化。在所提出的方程中，假设干燥和润湿过程中的土壤体积变化可以忽略不计，这对于大多数沙质土壤来说是一个合理的假设。基于所提出的理论，润湿扫描曲线由主干燥曲线估算。本文提出的方法的结果已与已发表文献中的实验数据进行了比较。在测量的和估计的润湿扫描曲线之间发现了令人满意的一致性。因此，推荐使用本文提出的方程从SWCC的拟合参数估计润湿扫描曲线的方法。