Investigation on unfrozen water content models of freezing soils

Unfrozen water content is a significant hydro-thermal property in numerical modeling cold regions. Although numerous models have been developed to mimic the variation of unfrozen with subzero temperature, comprehensive evaluation scarce. This study collected total 29 and divided them into four categories, namely, theoretical models, soil characteristic curve (SWCC)-based empirical estimation models. These were evaluated 1278 experimental points from 16 studies covering multiple types, including 24 clays, 18 silty 7 silts, 19 sands, 10 sandstones. Root mean square error average deviations applied judge performance these Most can well simulate relationship between temperature. Among aforementioned categories Lizhm et al. model, Fredlund Xing (C=1)-Wen Kozlowski model performed best their respective categories. Compared rest three be predict temperature by some easy-to-obtain physical parameters provide guidance for development