Abstract
Influence of void ratio on the shear stress increment due to dailatancy is examined by unsaturated triaxial compression test. The shear stress increment is caused by the positive dailatancy (dilation) at dense sand, and increases shear strength. Linear relation is found between the shear stress increment and state parameter at failure state. State paramenter is defined as ‘e (present void ratio) - ecri. (critical void ratio)’. Critical void ratio is affected by present stress condition. As the state parameter increases, the shear stress increment decreases. And this decreases until 0 at ‘state parameter is 0’. Same linear relation between shear stress increment and state parameter at any moment during shear is also confirmed.
