Unfrozen water content has an important influence on the physical and mechanical properties of frozen soil. Little research has been done on unfrozen water content of permafrost in the Northeast Region, China, so the experimental investigation was performed on Mohe permafrost (4 kinds of samples were taken from 4 kinds of undisturbed frozen soil) based on NMR method, and the relationship and between frozen temperatures (-1°C, -4°C, -7°C, -11°C, -14°C, -16°C) and unfrozen water content was obtained. The test results indicate that, Unfrozen water content decreased with the reduction of frozen temperature of permafrost and there was a power function relationship between unfrozen water content and frozen temperature. The unfrozen water content reduction of No.3 sample was the slowest, because it had the lowest water content and the least frost-heave and thawed amount. It also can be attained that ice content of Mohe permafrost became more and more, but bound water and free water content got less and less while frozen temperature fell continuously.
Exchangeable cations (Cu2+, Zn2+) effects on unfrozen water content in clay-water system using 1H NMR method
