Modeling soil behaviors under principal stress rotations

This paper presents an elastoplastic soil model considering the Principal Stress Rotation (PSR). The model is developed on the basis of a well-established kinematic hardening soil model using the bounding surface concept. The impact of the stress rate generating the PSR is treated independently, and is added to the base kinematic hardening model. The significance of independent treatment of the PSR stress rate in the soil model is demonstrated through comparing the simulations of soil stress-strain responses by using the base soil model and the modified model in the paper. Various test results in different sands under both drained and undrained conditions are simulated, and the new model gives better simulations involving the PSR induced volumetric strain and liquefaction. The paper also discusses the simulations and experiments of sand responses under multiple PSRs.