Dependence of unfrozen water content in unsaturated frozen clay soil on initial soil moisture content

Abstract

The unfrozen water content in an unsaturated frozen light clay soil having a range of initial soil moisture contents was measured independently using TDR and NMR in order to investigate the relationship between the unfrozen water content within a frozen soil and the initial soil moisture content. Unfrozen water contents measured by TDR and NMR were highly correlated and it was evident that the amount of unfrozen water in contact with ice at a given temperature was in proportion to the initial soil moisture content significantly. Since the effect of solutes in soil on the osmotic potential was negligible, a plausible interpretation for the dependence of the unfrozen water content on the initial soil moisture content was assumed to be the matric potential of unfrozen water being affected by both soil particles and ice.

Key words:

• frozen soil
• NMR
• TDR
• unfrozen water