Elastoplastic Stress-Strain Theory for Cohesionless Soil

Based on the results of cubical triaxial tests on Monterey No.0 Sand, an elastoplastic stress-strain theory was developed for cohesionless soil. The theory incorporates a new failure criterion, a new yield criterion, a new flow rule, and an empirical work-hardening law. The theory is applicable to general three-dimensional stress conditions and it models several essential aspects of the soil behavior observed in experimental investigations: nonlinearity, the influence of σ3, the influence of σ2, stress-path dependency, shear dilatancy effects, and coincidence of stress increment and strain increment axes at low stress levels with transition to coincidence of stress and strain increment axes at high stress levels. Results of cubical triaxial tests, torsion shear tests, and tests performed using various stress-paths were analyzed using the theory, and it was found that the stress-strain and strength characteristics observed in these tests were predicted with reasonable accuracy.