Comparison of the hydraulic conductivity between saturated frozen and unsaturated unfrozen soils

Abstract

Knowledge of the hydraulic conductivity of warm frozen soil is crucial for accurately calculating the deformation of buildings built in permafrost, and the objective of this study is to provide an experimental and theoretical method for obtaining the hydraulic conductivity of warm saturated frozen soil. The permeability experiments were carried out on warm frozen soil in the low temperature rock triaxial testing system, which provides a precise measurement of the water flow rate through the warm frozen soil. Repeated experiments were conducted to verify the validity of the experimental results. Subsequently, based on the experimental results and given the shortcomings of the ice impedance model, the equivalent model was proposed to predict the hydraulic conductivity of saturated frozen soil. The model suggested that saturated frozen soil and unsaturated unfrozen soil with the same liquid water content have the same hydraulic conductivity. To illustrate the validity of the model, the predictions of seven hydraulic conductivity models for unsaturated unfrozen soil were compared with the measured hydraulic conductivity of saturated frozen soil. The results show that the predictions are close to the measured data, which shows the validity of the model. Thus, the hydraulic conductivity of saturated frozen soil can be directly predicted by the hydraulic conductivity model for unsaturated unfrozen soil. The results provide a new method for obtaining the hydraulic conductivity of saturated frozen soil, which can provide a reference for the design and construction of buildings built in permafrost.