A new method to estimate the soil freezing characteristic curve

The soil freezing characteristic curve (SFCC) defines the relationship between unfrozen water content and temperature. It is an important soil parameter in cold regions, but it is not easy to obtain, especially in the field. This paper proposes a method to indirectly estimate the SFCC for both fine-grained and coarse-grained soils by using the one-measurement SFCC method. From regression analysis, the parameters of the van Genuchten SFCC model can be expressed as functions of an adjustable parameter x. The SFCC of a soil sample contained three different zones, and sensitivity analysis indicated that the measured point in Zone 2 provided the most reliable SFCC estimation results. The proposed model and four widely acknowledged models were compared and evaluated with 33 fine-grained soils and 9 coarse-grained soils. The results showed that the proposed model provided the best estimation of the SFCC among the five models. This result also indicated that the proposed model provided a better estimation of the SFCC for fine-grained soils. This study provides a reliable approach to develop an SFCC estimation model with the one-measurement SFCC method.