FIELD TECHNIQUES FOR MEASURING HYSTERETIC SOIL HYDRAULIC PROPERTIES OF UNSATURATED SANDY SOILS

Abstract

A new in-situ permeability test of determining soil hydraulic properties in the near surface of unsaturated sandy soils is proposed. The constant head infiltration test and the gravity drainage test were performed continuously. The transient soil water content during these tests were measured by a portable soil moisture device. The inverse solution of unsaturated soil hydraulic functions was applied to independently measured transient water content data for wetting and drying process to consider hysteretsis phenomenon of unsaturated soil hydraulic properties. The utility of our proposed method is demonstrated by using numerical models and experimental data of unsaturated dune sands.