Abstract
A three-dimensional swelling deformation of bentonite-sand mixtures is investigated. It is confirmed that the magnitude of volumetric strain εv due to wetting depends mainly on mean principal stress p regardless of principal stress ratio R while the magnitude of deviator strain (εa-εr) induced by wetting depends on principal stress ratio R regardless of mean principal stress p. A linear relation exists between montmorillonite void ratio em (defined as a ratio of water volume to montmorillonite volume) and mean principal stress p in their log scales. This relation between montmorillonite void ratio em and mean principal stress p is independent of initial dry density, mixing rate of bentonite and sand, and principal stress ratio R. In addition, there is a linear relation exists between deviator strain log(εa-εr) and principal stress ratio R.
