Pore-Morphology-Based Estimation of the Freezing Characteristic Curve of Water-Saturated Porous Media

초록

Assessment of freezing effects on soil requires estimating the soil freezing characteristic curve (SFCC)-the variation of unfrozen water content with temperature. The existing methods for obtaining SFCCs often involve either costly experiments or heuristic inference from water retention data. Here, we propose a pore-morphology-based method for simple and efficient estimation of the freezing characteristic curve of water-saturated porous media, whereby the pore-scale configurations of water and ice phases are simulated in a digital image of porous microstructure. Idealizing the pore space as a system of overlapping spherical pores, the method simulates the freezing process with the Gibbs-Thomson equation that can consider freezing-point depression-a decrease in the freezing point due to spatial confinement-based on thermodynamics. For validation, we apply the proposed method to estimate the SFCC of a field soil for which the experimental freezing characteristics data are available. Results show that even with a digital pore image extracted from a surrogate discrete-element packing of the soil, the proposed method provides an SFCC very close to the experimental data. A pore-morphology-based method is proposed to estimate the freezing characteristic curve of water-saturated porous media The Gibbs-Thomson equation and the sphere insertion method are combined to incorporate freezing point depression The proposed method is validated against experimentally measured freezing characteristic data of a field soil

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