Determination of Lean Clay Hydraulic Conductivity Function at Three Hierarchical Levels

Abstract

The main problem in unsaturated flow modeling is the costly, tedious and time consuming process of hydraulic conductivity function measurement. Fredlund divided the assessment of unsaturated soil properties into a hierarchical system involving four levels. This paper shows the procedures suggested and conducted to estimate a lean-clay-hydraulic-conductivity function at three hierarchical levels. The hydraulic conductivity function was obtained under levels 2, 3 and 4. Level 1 (i.e. direct measurement) was not considered. Level 2 was divided in Level 2a and Level 2b, measurement of matric suction with pressure plate and filter paper, respectively. The most common equations, algorithms and estimation methods were analyzed, selected and applied. It was observed Level 2b analysis is the best for the lean clay studied.