Hypoplastic modeling of inherent anisotropy in normally and overconsolidated clays

Inherent anisotropy is often observed in natural clays. This paper presents a hypoplastic constitutive model to describe the inherent anisotropy of normally and overconsolidated clays. A stress transformation technique is used to include the nonlinear failure criterion. A fabric tensor for inherent anisotropy is introduced, and its evolution provides an important link between the loading direction and the fabric orientation. Moreover, an updated internal tensor is coupled with the stress tensor to reflect the consolidation history and fabric evolution. The model is able to reproduce the salient behaviour of normally and overconsolidated clays with different bedding angles under various loading conditions.