A new and relatively simple method to numerically solve the equations for frost heaving of soil is described in this thesis. The model, called RIGIDICE, exploits two physical approximations. The first treats the behavior throughout one lensing cycle (period which a lens is born and grows to maturity) as matching those of a corresponding zone in a "steady state" system, i.e., one involving an endless succession of identical lensing cycles. The second approximation treats that process as if the instantaneous fluxes of matter and energy at the beginning and end of each lensing cycle equaled the fluxes averaged over the entire lensing cycle.; Important to this model are the choices of formulae which ostensibly represent functional relationships between pertinent physical properties of a given soil. These input functions include: thermal conductivity (K(,h)), a stress partition factor ((chi)), and, most critically, the hydraulic conductivity (K(,w)) and the unfrozen water content (W) of frozen soil. It is useful to express these functions in terms of dependence on a variable (phi), which is the difference between the pressures of ice and water coexisting within soil pores.; Experimental measurements of W and K(,w) were made in a novel constant-stress dilatometer/permeameter. The measured data were then fitted to simple formulae. Upon further analysis of the data, it was found that they were probably somewhat misleading and explanations for this conclusion are given.; Experimental results of heave tests with the same soil (provided by a colleague working in an independent laboratory) were compared with predicted outputs from RIGIDICE. While predictions relating to rate of heave, rate of penetration and load being heaved were in rather good agreement, predictions relating to thermal gradients could not be reconciled with actual data. Clearly the model is imperfect but it may nevertheless be of some practical value pending development of superior techniques for evaluating input functions representative of a given soil.
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