Thermal conductivity of soils is significant on the thermal simulations in cold region engineering. Based on the generalized thermal conductivity for geotechnical materials, a thermal conductivity model for saline soil was proposed in this paper. At the micro level, the microstructure composition of sodium sulfate soils in the proposed model was redefined. Macroscopically, the variation of salt crystals and ice crystals with temperature and the relationship between the arrangements of components (i.e., liquid water, ice, soil particles) of saline soil were studied. Shape parameters α, β, τ were adopted to define the volume proportion of needle shape soil particles, spherical shape soil particles and disk shape soil particles, respectively. Besides, the proposed thermal conductivity model considered the heat loss due to the heat radiation in the measurement process. Furthermore, the accuracy of the proposed model was verified by the experimental data. The results showed that the soil particles can be defined as SWCA (i.e., soil particles, water, crystals mixture of salt and ice, air) four-layer concentric structure in the calculation of the thermal conductivity model of saline soil. Shape parameters have significant influence on simulation results. By comparing test data with calculated values, it can be found that at positive temperature, silty clay soil particles are mainly spherical (β = 0.5) and disc-shaped (τ = 0.5), while the sandy soil and soil-rock particles are more similar to the needle shape (α = 1.0). With the decrease of temperature, the particle parameters of silty clay soil change, β decreases to 0, τ increases to 0.75, and α increases to 0.25. However, at negative temperature, the soil particles of sandy soil and loess are still mainly needle-shaped (α = 1.0).

土壤热导率在寒冷地区工程热模拟中具有重要意义。基于岩土材料的广义导热系数，本文提出了盐渍土的导热系数模型。在微观层面，重新定义了所提出模型中硫酸钠土壤的微观结构组成。宏观上，研究了盐渍土中盐晶和冰晶随温度的变化及其组分（即液态水、冰、土壤颗粒）排列之间的关系。形状参数α ，β ，τ分别定义了针状土粒、球状土粒和圆盘状土粒的体积比例。此外，所提出的热导率模型考虑了测量过程中由于热辐射引起的热损失。此外，实验数据验证了所提出模型的准确性。结果表明，在盐渍土导热系数计算中，土壤颗粒可定义为SWCA（即土壤颗粒，水，盐和冰的晶体混合物，空气）四层同心结构。形状参数对仿真结果有显着影响。将试验数据与计算值对比可知，在正温度下，粉质黏土颗粒以球形为主（β  = 0.5）和圆盘状（τ  = 0.5），而沙土和土石颗粒更接近于针状（α  = 1.0）。随着温度的降低，粉质黏土的颗粒参数发生变化，β减小到0，τ增大到0.75，α增大到0.25。但在负温度下，沙土和黄土的土壤颗粒仍以针状为主（α  =1.0）。