An Approach to Estimate Wetting Path of Soil–Water Retention Curve from Drying Path

Abstract

The Soil–Water Retention Curve (SWRC) is an important part of any constitutive relationship for unsaturated soils. The SWRC is a hysteretic curve, and geotechnical problems such as unsaturated slope stability analysis can lead to different results based on each branches. Although the majority of SWRC models can just predict the initial drying curve, the wetting path in many practical projects is critical and in fact occurs. In this research, an approach is presented to estimate the wetting path of genetic-based model as a sample of accurate models using initial drying. For this purpose, based on Feng and Fredlund (in: Proceedings of the 52nd Canadian geotechnical conference, Regina, Sask, 1999) hysteresis model of SWRC and using more than 180 soil samples, which are results from pressure plate tests carried out on clay, silty clay, sandy loam and loam, statistical values are suggested for the gravimetric water content difference of main drying and wetting curves at various suctions. The results show acceptable accuracy of the method.