Predictions of infiltration and redistribution and associated contaminant transport in soils require specification of complex material-dependent relationships between fluid pressures, temperature, the degree of saturation with respect to the fluids present and the permeability of the soil with respect to each of these fluids. In climates where soil undergoes freeze/thaw cycles, long-term predictions of flow and transport are further complicated by the need to account for the effects of liquid/solid phase change.

While we typically observe flow and transport phenomena on the porous medium continuum scale, the behaviors of interest are controlled by interactions between phases occurring at sub-continuum scale interfaces. This fact has motivated the development of network or lattice models which reproduce continuum scale phenomena by simulating pore scale events in an interconnected lattice of many pores. In previously reported research, this model has been used by the author and coworkers to investigate the effect of heterogeneity on the (isothermal) relationship between fluid pressures and saturations, the effect of temperature on the this relationship, the relationship between temperature and liquid water content for fully water saturated soils, and the effect of correlation in pore structure on the (isothermal) relationship between fluid pressures and permeabilities.

For the work reported here, the model has been extended to include freezing/thawing of partially water saturated soils. The expanded model is used to generate relationships between temperature, fluid pressures and permeability for a variety of soils. Comparisons between model results and laboratory results reported in the soils literature will be presented.

Lin A. Ferrand
Center for Water Resources and Environmental Research
Civil Engineering
City University of New York (T-110)
New York, NY 10031
Telephone: 212-650-8017
Fax: 212-650-6965
E-mail: lf@ce-mail.engr.ccny.cuny.edu