The processes of freezing–thawing and hydration–dissociation change the content of liquid water that coexists with ice or hydrate in porous media, such as frozen soils and hydrate-bearing sediments, changing their physicomechanical properties. In this study, a generalized phase equilibrium equation is presented for both frozen soils and hydrate-bearing sediments by considering the capillary and osmotic pressures. The liquid water content is related to temperature depression, plotted as the soil freezing characteristic curve (SFCC) or the soil hydration characteristic curve (SHCC), by combining the generalized phase equilibrium equation and the soil-water characteristic curve (SWCC). From the SFCC or the SHCC, the phase equilibrium surface can be calculated in the space of temperature, pressure, and liquid water content. The proposed generalized phase equilibrium equation and the model of SFCC and SHCC can help to estimate the physicomechanical properties that depend on the fraction of the liquid or solid phase in porous media. Finally, the SHCC is employed to analyze the dissociation of hydrate-bearing sediments using various methods.

中文翻译：

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多孔介质冻结和水化特性的比较

冻融和水化分解过程改变了多孔介质（如冻土和含水合物沉积物）中与冰或水合物共存的液态水的含量，从而改变了它们的物理力学性质。在这项研究中，通过考虑毛细管和渗透压，提出了冻土和含水合物沉积物的广义相平衡方程。液态水含量与温度下降有关，结合广义相平衡方程和土壤-水特征曲线（SWCC），绘制为土壤冻结特征曲线（SFCC）或土壤水化特征曲线（SHCC）。根据 SFCC 或 SHCC，可以在温度、压力和液态水含量的空间中计算相平衡表面。所提出的广义相平衡方程和 SFCC 和 SHCC 模型有助于估计依赖于多孔介质中液相或固相分数的物理机械特性。最后，SHCC 用于使用各种方法分析含水合物沉积物的分解。