Freeze-thaw action of rocks has caused many engineering geological disasters in cold regions. Estimation of the freeze-thaw damage degree and strengths loss of rocks are crucial for the prevention of freeze-thaw disasters. The main aim of this research is to investigate the influence of water saturation on the deterioration of rocks under freeze-thaw and find the best evaluation index. P-wave velocity, elastic modulus and porosity, as the widely used indexes, were adopted to define the freeze-thaw damage variables and predict the UCS loss under freeze-thaw. The change law of these three indexes shows that the critical water saturation for causing a considerable freeze-thaw damage of sandstones is approximately 60%∼80%. P-wave velocity is proved to be a competitive nondestructive parameter, which can be measured easily and correctly without any time-consuming mechanical test. In addition, P-wave velocity can be well used to predict strength loss of rocks under freeze-thaw by performing a statistical analysis of experimental data. It is suggested that the P-wave velocity may be the primary and best index to quantify the freeze-thaw damage degree of rocks with different water saturations comparison with the other two indexes. This study can provide a better understanding of the deterioration of physico-mechanical properties for unsaturated rocks and give a reference for the selection of freeze-thaw evaluation indexes.

岩石的冻融作用在寒冷地区造成了许多工程地质灾害。估计岩石的冻融破坏程度和强度损失对于预防冻融灾害至关重要。本研究的主要目的是研究含水饱和度对冻融条件下岩石劣化的影响，并找到最佳评价指标。采用纵波速度、弹性模量和孔隙率作为广泛使用的指标来定义冻融损伤变量，预测冻融条件下的UCS损失。这三个指标的变化规律表明，引起砂岩显着冻融破坏的临界含水饱和度约为60%～80%。P波速度被证明是一个有竞争力的无损参数，无需任何耗时的机械测试即可轻松正确地进行测量。此外，通过对实验数据进行统计分析，P 波速度可以很好地用于预测冻融条件下岩石的强度损失。与其他两个指标进行比较，认为纵波速度可能是量化不同含水饱和度岩石冻融破坏程度的主要和最佳指标。该研究可以更好地了解非饱和岩石物理力学性质的恶化情况，为冻融评价指标的选择提供参考。与其他两个指标进行比较，认为纵波速度可能是量化不同含水饱和度岩石冻融破坏程度的主要和最佳指标。该研究可以更好地了解非饱和岩石物理力学性质的恶化情况，为冻融评价指标的选择提供参考。与其他两个指标相比，建议纵波速度可能是量化不同含水饱和度岩石冻融破坏程度的主要和最佳指标。该研究可以更好地了解非饱和岩石物理力学性质的恶化情况，为冻融评价指标的选择提供参考。