ABSTRACT
In this paper, the study of conservative solutes released into unsaturated homogeneous and layered soils has been addressed through physical modelling in a geoenvironmental centrifuge. Because independent long term modelling under a variety of controlled boundary conditions can be performed without the need to establish soil properties, centrifugation is an ideal technique for obtaining data sets for numerical simulation validation or calibration. Physical testing in the centrifuge was used to calibrate soil-water characteristic curve, hydraulic conductivity function, and molecular diffusion function predictions from the commercially available program SoilVision. Centrifuge modelling was used to simulate the 2-D transport of NaCl solution releases into unsaturated soil systems. Pore water concentrations were measured during centrifugation (in-flight) at various depths and were determined, along with volumetric water content, at the end of each modelling sequence. Two model series were performed and the results compared to predictions from the commercially available software SEEP/W and CTRAN/W.
