Estimation of hydraulic conductivity of saturated frozen soil from the soil freezing characteristic curve.

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 10-6 cm/s and 10-11 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.