Vapour Equilibrium and Osmotic Technique for Suction Control

The vapour equilibrium method and osmotic technique have gained widespread acceptance as reliable methods for controlling relative humidity and thereby suction in soil specimens. The ability to impose suction on soil specimens allows for drying and wetting stress paths to be imposed to evaluate resulting changes in strength, deformation and flow characteristics. The two methods presented and discussed in this paper have been adapted for use with a number of traditional laboratory tests including the oedometer, direct shear and triaxial tests. This report provides a summary of some recent developments and knowledge regarding the use of these techniques highlighting the limitations and drawbacks of the methods.