The phase transition of pore water in porous rock is closely related to the pore size distribution (PSD) based on thermodynamic equilibrium, and the ice formation is further affected by the internal hydraulic pressure and external confinement. This study quantitively assesses the risk of frost damage for rocks with/without surrounding pressures through a thermodynamic approach. First, an empirical PSD model is established and compared with experimental results, which is further adopted to calculate water saturation and ice volume under different humidity and temperature conditions. Then the depression of freezing point is discussed under undrained condition by dividing these rocks into three typical groups in terms of porosity and strength. Moreover, confinement by the high surrounding stress is considered for underground structures to study its influence on the ice formation process. Finally, correlation is found between the lowest bearable temperature and the expression of the porosity and strength of rocks, enabling a convenient assessment of frost damage risk for the rocks.

多孔岩石中孔隙水的相变与基于热力学平衡的孔径分布（PSD）密切相关，冰的形成进一步受到内部水压和外部约束的影响。本研究通过热力学方法定量评估有/无周围压力的岩石冻害的风险。首先，建立经验PSD模型并与实验结果进行比较，进一步用于计算不同湿度和温度条件下的水饱和度和冰量。然后通过将这些岩石从孔隙度和强度上分为三个典型组来讨论不排水条件下的冰点降低。而且，考虑地下结构高周围应力的约束，研究其对冰形成过程的影响。最后，发现了最低可承受温度与岩石孔隙度和强度的表达之间的相关性，可以方便地评估岩石的冻害风险。