Prediction of Unsaturated Hydraulic Properties of Dune Sand on Drying and Wetting Paths

Several geotechnical and geo-environmental problems involve water flow through unsaturated porous media. Generally flow is governed by the classical Richard’s equation. The most important factor entering the governing transfer equation is, with no doubt, the unsaturated hydraulic conductivity of the soil. The laboratory procedures used to measure this property are tricky, error-prone and time consuming, in particular for low suction range. As a result many researchers have proposed different empirical and statistical models for estimating the unsaturated hydraulic properties from easily measured soil properties. In this paper we study the reliability of such indirect methods for predicting the hydraulic conductivity of dune sand widely present in the Algerian Sahara. The results obtained are promising and attest clearly of the major contribution that may bring along the hydraulic property prediction models to the unsaturated soil mechanics practice