PERMEABILITY FUNCTIONS FOR UNSATURATED SOILS

This paper examines the three categories of permeability functions for unsaturated soils, including empirical, macroscopic, and statistical models. The theoretical backgrounds and performance of each category a re examined against various experimental data. The paper also shows th at it is possible to degenerate statistical models to macroscopic mode ls and then to empirical models. A new empirical equation for the perm eability function is suggested. The statistical model demonstrates goo d performance and can be readily applied. In some cases the performanc e of the statistical model can be further improved with the introducti on of a correction.