PNNL

Abstract

Critical path analysis from percolation theory is applied to soils with pore space compatible with a (sometimes complex) fractal description. The fractal descriptions chosen were suggested by the particle-size distributions of two different soils at the US Department of Energy Hanford Site. One of the two soils exhibited a rather unusual bimodal particle-size distribution, and was therefore treated as a ?dual? fractal. The results were then compared with the measured hydraulic properties of these two Hanford Site soils. The analysis yielded excellent agreement with experiment in most investigated properties without use of fitting parameters. The agreement was at least sufficient to aid in the interpretation of both unusual physical phenomena, relating to the bimodal particle-size distribution, and in understanding the choice of parameters of more traditional phenomenologies for the hydraulic properties of the systems, such as greatly differing residual moisture contents for the two soils deduced from the van Genuchten phenomenology.