This paper describes theoretical studies of the Winchendon field performance data using a computer model, FROSTl, developed by the US Army Corps of Engineers Cold Regions Research and Engineering Laboratory (CRREL). The Winchendon field test site was constructed by the Massachusetts Department of Public Works (MDPW) during the fall of 1977. Data on frost heave, frost depth, and thaw weakening were then obtained during the next three winter seasons. FROSTl assumes one-dimensional vertical heat and moisture flux, and is intended for use on problems of seasonal freezing and thawing of nonplastic soils that range from silts to silty sands and gravels above the water table. These simulations have shown that the computations are sensitive to the input thermal and hydraulic soil parameters, porosities, and boundary temperatures and pressures. Nevertheless, they provide guidance in the selection of input parameters for FROSTl. Parametric studies were made to provide design curves that show, for two water-table depths, the reduction in maximum heave with increasing amounts of frost protection. These curves will assist designers in evaluating the required depth of frost protection and in particular the effects of only partial frost protection in situations where factors such as buried utilities or economics preclude the use of non-frost-susceptible (NFS) materials lo the full frost depth.

This paper describes theoretical studies of the Winchendon field performance data using a computer model, FROSTl, developed by the US Army Corps of Engineers Cold Regions Research and Engineering Laboratory (CRREL). One objective of these studies was to develop relationships between physical properties of the soil and model input parameters so that the theoretical model could then be used as a design tool to predict frost heave and frost penetration versus time for trial design pavement cross sections. Computations of pore pressures and settlements during the thaw period might then be incorporated into mechanistic design approaches such as those described by AASHTO (1).