Application of a fully predictive model for secondary frost heave

Laboratory core freezing data for a Calgary silt are used to validate the secondary frost-heave model of Fowler and Krantz. This model is based on the model of O'Neill and Miller, but incorporates scaling and asymptotic analysis to make the complex physics of the freezing fringe more tractable and employs a more realistic thermal regelation mechanism for ice movement. Although this model does not involve any adjustable parameters, owing to insufficient soil-characterization data, it was necessary to fit one parameter in the equation describing the hydraulic conductivity of the frozen soils. However, this parameter was found to correlate very well with the porosity of the Calgary silt samples. These results were used to develop an equation for predicting the hydraulic conductivity of frozen Calgary silt as a function of soil porosity and unfrozen water volume fraction. These studies strongly support the predictive capability of the Fowler and Krantz model which because of its simplicity can be readily extended to incorporate solutal effects on freezing, soil compressibility, and differential frost heave.