Abstract
Unsaturated soils with bimodal pore structures, such as many residual and colluvial soils, are widespread in nature. Bimodal pore structures can noticeably influence their soil–water retention behaviour. Estimating the bimodal soil–water retention curve (SWRC) accurately has become critical in both theoretical research and engineering practice. In this paper, a novel equation to simulate the bimodal SWRC of unsaturated soils is proposed. The proposed bimodal SWRC equation not only provides higher simulation accuracy for bimodal SWRCs compared to other equations, but it also shows good agreement with experimental data from different types of soils. Moreover, the relationships between bimodal SWRC variables (i.e., air entry value, inflection point, and slopes at transition zone) and the best fitting parameters are presented. Finally, a practical approach is developed to estimate the bimodal relative permeability of unsaturated soils based on the proposed bimodal SWRC equation. The results are convincingly demonstrated that there is good agreement between the predicted and measured relative permeability coefficients of unsaturated soils in the literature.
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Acknowledgements
The authors express their gratitude for the Grants provided by the National Natural Science Foundation of China (No. 42272312), the China Postdoctoral Science Foundation Funded Project (Grant No. 2023M732252), the Zhejiang Provincial Xinmiao Talents Program (No. 2022R405B076).
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Gao, Y., Fu, Y., Chen, J. et al. A novel equation for simulating the bimodal soil–water retention curve of unsaturated soils. Acta Geotech. (2024). https://doi.org/10.1007/s11440-024-02233-y
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DOI: https://doi.org/10.1007/s11440-024-02233-y