A New Critical State-Based Constitutive Model in Multilaminate Framework

ABSTRACT: A new constitutive model based on critical state theory is introduced to model behavior of granular material. This new model is a bounding surface plasticity model in multilaminate framework that allows capturing the effects of inherent and induced anisotropy as well as principal stress rotation. Multilaminate framework is a tool and cannot predict the behavior of material independently from a constitutive model. Multilaminate framework is semi-micromechanical tool based on formulating a number of planes with varying orientations over a virtual unit sphere around a stress point. The constitutive equations of the model are derived within the context of non-linear elastic behavior and plastic sliding of interfaces of predefined planes from multilaminate framework. Presented here are multilaminate framework details, the constitutive equations of the original bounding surface model in the multilaminate framework and sensitivity analysis of key material parameters that clearly show the capabilities and flexibility of the presented constitutive model in predicting drained and undrained behavior of granular material.