An Elasto-Viscoplastic Constitutive Model for Clay based on a Transformed Stress Tensor

Abstract

It has been well known that the behavior of natural clay is anisotropic. One of the reasons is that the behavior is strongly affected by the histories of stress, strain, temperature and chemical reactions. This type of anisotropy is called ‘Stress induced or structural anisotropy’. On the other hand, behavior of clay strongly depends on the current stress state. The current stress sensitivity is one of the salient features of granular materials. An anisotropic stress state results in an psedoanisotropic deformation behavior. This type of behavior contains the intermediate stress dependency of the material behavior. In the present paper, an noncoaxial elasto-viscoplastic constitutive model for clay is proposed by introducing the transformed stress tensor.