ABSTRACT
The coupled effects of changes in suction and stress on the response of unsaturated soils is a fundamental aspect to consider when dealing with unsaturated soils. The difficulty of measuring and controlling suction is one of the reasons why the development of the mechanics of unsaturated soils has not been as advanced as that of saturated soils in which water pressure is positive. In relation with the significant increase in research efforts carried out during the last two decades in the mechanics of unsaturated soils, various techniques of measuring and controlling suction have been adopted and/or further developed. These techniques have been described in detail in various papers (including Ridley and Wray 1996, Agus and Schanz 2005, Rahardjo and Leong 2006).
