Modeling principal stress rotation for anisotropic sand

This paper extends a constitutive model previously developed by the authors to model the anisotropic sand behavior during cyclic rotation of principal stress axes. A new anisotropic stress tensor is defined by transforming the principal stresses during the rotation, and is then incorporated to formulate the incremental form of the constitutive relation for anisotropic soil subjected to cyclic load. All the model parameters can be conveniently calibrated by triaxial compression/extension tests. The new model is validated by simulating the behavior of Toyoura sand subjected to rotational shearing and good comparison is observed with the experimental data.