A unified method to describe the influences of intermediate principalstress and stress history in constitutive modelling

摘要

A simple and unified method for considering the influences of the intermediate principal stressand the stress histories on the deformation and the strength of soils, which obeys isotropic hardening rule inmodified stress space, is proposed. The concept of the modified stress ty, which was proposed before by ourgroup to describe the influence of the intermediate principal stress, is extended to a new stress tensor t_(ij)to con-sider the fabric change of soils due to the variations of the intermediate principal stress and the stress histories.The evolution rule of t_(ij)is established referring to past experimental evidences. In this paper, the modified stresst_(ij) is applied to the isotropic hardening elastoplastic model named subloading t_(ij) model. The proposed modelis verified by comparing the calculated results with the experimental results of true triaxial tests and directionalshear tests on medium dense sand.