State Key Laboratory of Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China.
State Key Laboratory of Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Sci Total Environ. 2020 Jan 1;698:134132. doi: 10.1016/j.scitotenv.2019.134132. Epub 2019 Aug 30.
Knowledge of hydraulic conductivity is crucial for determining water movement in frozen soil, and the objective of this study is to introduce the soil freezing characteristic curve to estimate the hydraulic conductivity of saturated frozen soil. Based on the non-uniform tortuous capillary bundle model and the assumption that the ice was first formed in the pores with largest size, a physical infiltration model of saturated frozen soil was developed. On the basis of this physical infiltration model, a new approach for estimating the hydraulic conductivity of saturated frozen soil was developed by using the Hagen-Poiseuille equation and Darcy's law. To verify the validity of this approach, five soil data sets, including 29 data points with hydraulic conductivity between 10 cm/s and 10 cm/s, were used to compare the predicted results and experimental data. The results show that the new approach fits the experimental data well. This approach is more convenient than the soil water characteristic curve in numerical modeling, and it can be used to describe the relationship between hydraulic conductivity and minus temperature. Moreover, the new approach and the results in this study maybe also can provide a reference for the research on water flow and the related numerical modeling in cold regions environmental engineering.
了解导水率对于确定冻土中的水分运移至关重要，本研究旨在引入土壤冻结特征曲线来估算饱和冻土的导水率。基于非均匀曲折毛细管束模型和假设冰首先在最大尺寸的孔隙中形成的假设，开发了饱和冻土的物理渗流模型。在此物理渗流模型的基础上，利用哈根-泊谡叶方程和达西定律，提出了一种估算饱和冻土导水率的新方法。为了验证该方法的有效性，使用了五个土壤数据集，包括 29 个导水率在 10 cm/s 到 10 cm/s 之间的数据点，对预测结果和实验数据进行了比较。结果表明，该新方法与实验数据拟合良好。与数值建模中的土壤水分特征曲线相比，该方法更方便，可用于描述导水率与负温之间的关系。此外，新方法和本研究的结果也可为寒区环境工程中水流及其相关数值建模的研究提供参考。
