在西部地区矿产资源开发和工程建设中，砂岩作为主要的工程地质含水层之一，冻融环境影响砂岩的力学及变形特性。为研究受冻融环境影响下受荷岩力学性能的劣化和损伤特性，以陕西地区红色细砂岩为研究对象，开展0、5、10、20和30次冻融循环试验和单轴压缩试验，获得冻融后砂岩的单轴压缩全过程应力–应变曲线和力学特征参数，对冻融岩石进行力学特征参数分析，建立冻融环境下岩石力学性能的劣化模型；基于冻融环境对岩石损伤的影响，考虑岩石在变形阶段中压密阶段的特点，建立考虑压密阶段修正统计损伤本构模型。结果表明：随着冻融循环次数的增加，岩石压密阶段的占比越来越大，峰值应也变逐渐增大，冻融循环前30次岩石发生脆性破坏，冻融循环30次后岩石脆性明显减弱，应变软化阶段明显；冻融循环前10次，力学特征参数损失率增长较快，之后明显减缓；冻融循环30次之后，峰值强度损失率为47.27%，弹性模量损失率为60.35%；其中力学特征参数损失率与冻融循环次数成一次线性增长，在建立的力学性能劣化模型中，冻融后岩石力学性能占比成指数递减，利用冻融环境下岩石的孔隙特征，可准确预测岩石在冻融环境作用下的峰值强度和弹性模量；考虑压密阶段的修正统计损伤本构模型与试验曲线拟合度更高，修正理论模型可对冻融受荷岩石力学性能劣化和损伤预测提供借鉴。

In the development of mineral resources and engineering construction in the western region, sandstone is one of the main engineering geological aquifers, and the freezing and thawing environment affects the mechanical and deformation characteristics of sandstone. In order to study the deterioration and damage characteristics of mechanical properties of loaded rocks under the influence of freeze-thaw environment, red fine sandstone in Shaanxi province was taken as the research object, and freeze-thaw cycle tests and uniaxial compression tests were carried out for 0, 5, 10, 20 and 30 times, and the stress-strain curve and mechanical characteristic parameters of the whole uniaxial compression process of frozen-thawed sandstone were obtained. The mechanical characteristic parameters of frozen-thawed rocks were analyzed, and the deterioration model of rock mechanical properties under freeze-thaw environment was established. Based on the influence of freeze-thaw environment on rock damage, considering the characteristics of rock compaction stage in deformation stage, a modified statistical damage constitutive model considering compaction stage is established. The results show that with the increase of freeze-thaw cycles, the proportion of rock compaction stage is increasing, and the peak value should also increase gradually. Brittle failure occurs in the first 30 freeze-thaw cycles, and the brittleness of rock is obviously weakened after 30 freeze-thaw cycles, and the strain softening stage is obvious. The loss rate of mechanical characteristic parameters increased rapidly in the first 10 times of freeze-thaw cycle, and then slowed down obviously. After 30 freeze-thaw cycles, the peak strength loss rate is 47.27% and the elastic modulus loss rate is 60.35%. Among them, the loss rate of mechanical characteristic parameters increases linearly with the number of freeze-thaw cycles, and the mechanical properties of rocks decrease exponentially after freeze-thaw. The peak strength and elastic modulus of rocks under freeze-thaw environment can be accurately predicted by using the pore characteristics of rocks under freeze-thaw environment. The modified statistical damage constitutive model considering the compaction stage has a higher fitting degree with the test curve, and the modified theoretical model can provide reference for the deterioration of mechanical properties and damage prediction of frozen-thawed rocks.