ABSTRACT
The specific procedures employed for determination of material parameters are then presented in connection with derivation of parameters for Antelope Valley sand. The elastoplastic stress-strain model originally developed for cohesionless soil reflects many of the characteristics of sand behaviour observed in laboratory tests. The plastic strains are initially smaller than the elastic strains, but at higher values of stress difference the plastic strains dominate the elastic strains. The conical yield surface may be curved in planes containing the hydrostatic axis, or it may be straight as in the original model. The collapse yield surface is shaped as a sphere with centre in the origin of the principal stress space. The elastoplastic stress-strain model presented is applicable to general three-dimensional stress conditions, but the material parameters required to characterize the soil behaviour can be derived entirely from the results of isotropic compression and conventional drained triaxial compression tests.
