This paper describes a heuristic approach that combines a limited number of experimental measurements with the random finite-element method (RFEM) to accelerate significantly the process of measuring the hydraulic conductivity of unsaturated soils. A microstructure-based RFEM model is established to describe unsaturated soils with distribution of phases based on their respective volumetric contents. The intrinsic hydraulic properties of each phase (soil particle, water and air) are applied based on the microscopic structures. The intrinsic permeability of each soil phase is first calibrated from soil measured under dry and saturated conditions, which is then used to predict the hydraulic conductivities at different extents of saturations. The results match closely the experimental data. The pore size parameter was obtained from the variations in hydraulic conductivity with degree of saturation; from this, the soil-water characteristic curve (SWCC) is predicted. The results show that the SWCC estimated matches very well with experimental data. Overall, this study provides a new modelling-based approach to predicting the hydraulic conductivity function and SWCC of unsaturated soils based on measurement at completely dry or completely saturated conditions. An efficient way to measure these critical unsaturated soil properties will benefit introducing unsaturated soil mechanics into engineering practice.

中文翻译：

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快速估算非饱和土壤导水率的程序

本文介绍了一种启发式方法，该方法将有限数量的实验测量与随机有限元方法（RFEM）相结合，可以显着加快非饱和土壤水力传导率的测量过程。建立了基于微观结构的RFEM模型，以描述基于各自体积含量的具有相分布的非饱和土壤。基于微观结构来应用每个相（土壤颗粒，水和空气）的固有水力特性。首先根据在干燥和饱和条件下测得的土壤对每个土壤相的固有渗透率进行校准，然后将其用于预测不同饱和度下的水力传导率。结果与实验数据非常吻合。孔径参数是根据水力传导率随饱和度的变化而获得的；据此，可以预测土壤水特征曲线（SWCC）。结果表明，SWCC估算值与实验数据非常吻合。总的来说，这项研究提供了一种基于建模的新方法，可以基于在完全干燥或完全饱和条件下的测量结果来预测非饱和土壤的水力传导率函数和SWCC。测量这些关键的非饱和土壤特性的有效方法将有益于将非饱和土壤力学引入工程实践。这项研究提供了一种基于建模的新方法，可以基于在完全干燥或完全饱和条件下的测量结果来预测非饱和土壤的水力传导率函数和SWCC。测量这些关键的非饱和土壤特性的有效方法将有益于将非饱和土壤力学引入工程实践。这项研究提供了一种基于建模的新方法，可以基于在完全干燥或完全饱和条件下的测量结果来预测非饱和土壤的水力传导率函数和SWCC。测量这些关键的非饱和土壤特性的有效方法将有益于将非饱和土壤力学引入工程实践。