On the Stress-Strain Behavior of a Sand

Some experimental results are presented to show that there exists a remarkable similarity between the response of a sand at high pressures and that of a normally consolidated clay at ordinary pressures. It is postulated, on this experimental fact, that a sand under high stresses is an isotropic hardening material as an intact clay may be, hence, the critical state concept is introduced for investigating the stress-strain behavior of a sand subjected to high pressures. Two kinds of high pressure triaxial compression tests, of which shear conditions are drained and constant volume, are performed on the Toyoura sand of dense state. It is shown that the predicted stress-strain relations, which are resulted from the theoretical equations that have been developed by Roscoe et al., are reasonably comparable with the observed stress-strain relations.