Predicting the hydraulic conductivity of frozen coarse-grained soils

Abstract

Hydraulic conductivity is crucial to revealing the mechanisms of frost damage in cold regions, while the hydraulic conductivity of coarse-grained soils during freezing process has rarely been considered. In this study, a new pattern that ice grows from the pore wall is used to describe ice formation in coarse-grained soils. In this pattern, unfrozen water confined in the pore center provides flow channels for liquid water migration. The relationship between distribution characteristics of flow channels and hydraulic conductivity can be established by redefining parameters such as porosity ϕe, hydraulic radius RH¯ and tortuosity Γ in the Kozeny-Carman equation. It thus generates a new hydraulic conductivity model for frozen coarse-grained soils. Comparing with measured result in the literature, it shows that the proposed model gives a better prediction than existing models, especially for sand. The proposed model can provide a useful tool for simulating water-heat transfer process of coarse-grained soils in cold regions.