In order to grasp the characteristics and mechanism of saline soil deformation under the coupling action of cooling and dynamic load, three types of subgrade fillings from the Qarhan-Golmud Highway in Qinghai-Tibet Plateau were selected as experimental soil samples for the experimental study. Firstly, the freezing temperature experiment was carried out on SS (sandy silt) and HS (high-sulfate silty clay). The test results showed that the freezing temperature of SS is -0.32°C, while that of HC (high-chloride silty clay) and HS will not freeze at -20°C, due to the presence of salt. Secondly, the three soil samples were subjected to deformation characteristic test under coupling action of cooling and dynamic load, respectively, and the time history curve of temperature gradient change, the time history curve of the change rate of deformation, and deformation rate were summarized. Finally, the model of deformation rate vs. time and the model of change rate of deformation vs. deformation rate under the coupling action of cooling and dynamic load are proposed. The test results found that (1) the cooling rate of the temperature gradient curve of the three soil samples showed a rapid cooling rate in the early stage, and it tends to stabilize in the later stage. The distance of the 0°C line from the top gradually decreases, which is affected by the freezing temperature and the salt content. (2) Affected by the freezing temperature and salt type, SS exhibits frost heave, and HS and HC appear to settlement. The final deformation is 1.0%, -0.73%, and -1.10%, respectively. (3) The model of deformation rate vs. time and the model of change rate of deformation vs. deformation rate under the coupling action of cooling and dynamic load were proposed and verified, which are helpful for the evaluation of engineering stability on saline soil subgrade fillings.

中文翻译：

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冷却与动荷载耦合作用对高盐度盐渍土变形特性的影响

为掌握冷却与动荷载耦合作用下盐渍土变形的特征及机理，选取青藏高原察尔罕至格尔木公路的3种路基填料作为试验土样进行试验研究。首先，对SS（砂质粉砂）和HS（高硫酸盐粉砂质粘土）进行冷冻温度试验。测试结果表明，SS的冻结温度为-0.32℃，而HC（高氯化物粉质粘土）和HS的冻结温度在-20℃时不会冻结，因为存在盐分。其次，对三个土样分别进行冷却和动载荷耦合作用下的变形特性试验，得到温度梯度变化的时程曲线、变形变化率的时程曲线、和变形率进行了总结。最后，提出了冷却与动载荷耦合作用下的变形率随时间变化模型和变形率随时间变化率模型。试验结果发现：（1）三个土样的温度梯度曲线的降温速率在前期呈现较快的降温速率，后期趋于稳定。0°C 线距顶部的距离逐渐减小，这受冻结温度和含盐量的影响。(2)受冻结温度和盐类的影响，SS出现冻胀，HS和HC出现沉降。最终变形分别为 1.0%、-0.73% 和 -1.10%。(3) 变形率随时间变化模型和变形变化率随时间变化模型