A practical approach to obtain the soil freezing characteristic curve and the freezing/melting point of a soil water system
Knowing that extensive field tests and laboratory tests are time consuming and expensive, this paper describes a practical approach to obtain crucial properties of frozen soil such as the soil freezing characteristic curve (SFCC) the freezing/melting point of a soil water system and its hydraulic conductivity by means of limited input data. Different models and empirical equations are combined to provide a closed formulation which can be used in computer simulations to account for moisture migration in partially frozen soils. Input data such as grain size distribution and dry bulk density suffice to obtain the aforementioned properties. Further consideration of the pressure dependence of the freezing/melting temperature of water/ice even allows accounting for the phase change point depression and thus the phenomena of pressure melting. The model is appropriate not just to represent qualitatively the SFCC of different soil types, but also to provide conformity between the model prediction and measured data of many soil types having a log normal grain size distribution. This user friendly approach is used as default setting of a newly implemented user defined soil model for frozen and unfrozen soil in the geotechnical finite element code PLAXIS 2D.