ABSTRACT
Volume change prediction of unsaturated soils is a matter of concern that will help geotechnical engineers to know the mechanisms which occur during saturation (wetting) or desaturation (drying) processes. Expansive and collapsible soils are given extra concern in the context of problematic soils due to the variety of behavior they have shown regarding their initial (prewetting) conditions. Meanwhile, swelling and swelling pressure of plastic clays have been investigated since the mid 20th Century. Holtz and Gibbs (1956) investigated effects of initial water content and dry density on swelling potential and swelling pressure (Figs. 1 and 2).
