ABSTRACT
It is generally recognized that the effective cohesion of unsaturated soil is influenced by the change in suction in unsaturated soil. By decreasing suction due to the increase in water content, the effective cohesion is decreased in unsaturated soil. The change in effective cohesion due to the change in water content has an influence on some problems such as slope stability and bearing capacity of shallow foundation. In this paper we consider the physical meaning of effective cohesion of unsaturated sandy soil on the scale of soil particle size and then propose to estimate the change in effective cohesion due to the change in water content quantitatively.
