Thermal conductivity of soils is a key parameter in determining the heat transfer and temperature field in thermal engineering. This paper developed a thermal conductivity model of soils with a consideration of the thermo-hydro-deformation interaction during a freezing process. The model was proposed based on the concept of normalized thermal conductivity, and integrated the temperature, volumetric unfrozen water content, porosity, mineralogy, solid particle type and frost heave. Then, the steps to calculate thermal conductivity of soils during a freezing process were illustrated. Additionally, compared with the other two widely used empirical models, i.e., model based on the apparent heat capacity method and model based on the Heaviside function, the proposed model was more effective and reasonable, while the other two models had some limitations in calculating thermal conductivity of soils during a freezing process. Moreover, the proposed model was comprehensively verified by the 32 soil samples, and the good agreements between the measured and model-calculated thermal conductivities of soils confirmed that the proposed model can be used to calculate the thermal conductivity of soils in the numerical simulations, and could also well reflect the effect of phase transition of water-ice on thermal conductivity of soils during a freezing process.

土壤热导率是确定热工程传热和温度场的关键参数。本文开发了土壤热导率模型，并考虑了冻结过程中的热-水-变形相互作用。该模型是基于归一化导热系数的概念提出的，综合了温度、体积解冻水含量、孔隙度、矿物学、固体颗粒类型和冻胀。然后，说明了计算冻结过程中土壤热导率的步骤。此外，与其他两种广泛使用的经验模型，即基于表观热容法的模型和基于Heaviside函数的模型相比，所提出的模型更加有效和合理，而另外两个模型在计算冻结过程中土壤的热导率方面存在一些局限性。此外，所提出的模型得到了 32 个土样的综合验证，土壤热导率实测值与模型计算结果吻合良好，证实所提模型可用于数值模拟中的土壤热导率计算，也可以很好地反映冻结过程中水冰相变对土壤热导率的影响。