Estimation of frost heave for stratified soil profile

An operational model for estimation of frost heave in field where stratified soil profile occurs is presented. The model is developed from the research model described and verified by Sheng and Knutsson (1993). Soil layers are first classified into frost-susceptible layers (FSL) or non-frost-susceptible layers (NFSL). In an FSL, both heat flow and water flow are considered and ice lensing can occur. In a NFSL, only heat flow is possible and no ice lensing is allowed. The governing equations for heat and mass transfer are established for the time period when the frost front is moving within FSL. Capillarity and unsaturation are also considered. The operational model is verified by field measurements of heave amounts. The computed values of heave are in a good agreement with the measured data. The applicability of the model to solving practical problems is demonstrated through example problems. The effectiveness of the commonly-used insulating materials in reducing frost heave is evaluated. The differential frost heave caused by the snow cover on road shoulders is estimated, as a function of the snow thickness. The effect of the ground water table on frost heave is also studied.