土壤热导率的预测准确性对地源热泵和钻孔热能等地热相关结构设计至关重要，基于土壤复杂、随机、自相似性的微观结构特征，使用分形理论，考虑土壤的孔隙率和颗粒排列等参数对土壤弯曲度的影响，建立三相土壤有效导热系数毛细孔物理模型和对应的有效导热系数数学模型，将模型预测结果与已有实验数据进行了对比。结果表明：增加土壤颗粒排列等参数后的模型对孔隙率在0.21 ~ 1的土壤热导率预测有较高的准确性，且不同孔隙率的三相土壤热导率与土壤颗粒排列阻塞参数有关，孔隙率越大、阻塞参数越小模型预测越接近实验结果；弯曲度改变对热电比模型的串并联比例有直接影响，土壤颗粒排列对弯曲度的影响随孔隙率的增大而减小，弯曲度与三相土壤热导率的变化趋势成反比。相关结果有助于地埋管与管外三相土壤换热效率的研究。

The prediction accuracy of soil thermal conductivity is crucial to the design of geothermal-related structures such as ground source heat pump and borehole heat. Based on the complex, random and self-similar microstructure characteristics of soil, by using fractal theory to consider the effects of soil porosity, particle arrangement and other parameters on soil curvature, a capillary physical model and a corresponding mathematical model of effective thermal conductivity of three-phase soil were established. The predicted results of the model were compared with existing experimental data. The results show that the model with the addition of soil particle arrangement and other parameters has higher accuracy in predicting the soil thermal conductivity with porosity between 0.21 ~ 1, and the three-phase soil thermal conductivity with different porosity is related to the soil particle arrangement blocking parameters. The larger the porosity and the smaller the blocking parameters, the closer the model prediction is to the experimental results. The bending degree has a direct influence on the series-parallel ratio of the thermoelectric ratio model. The influence of soil particle arrangement on the bending degree decreases with the increase of porosity, and the bending degree is inversely proportional to the change trend of the three-phase soil thermal conductivity. The relevant results are helpful to the research of the three-phase soil heat transfer efficiency of buried pipe and outside pipe.