Formulation of MIT‐E3 Constitutive Model for Overconsolidated Clays

This paper presents a generalized effective stress model for describing the rate‐independent behavior of normally to moderately overconsolidated clays (with OCRs less than 8) that exhibit normalized behavior. The model formulation comprises three components: (1) An elastoplastic model for normally consolidated clay including anisotropic and strain‐softening behavior; (2) equations to describe the small strain nonlinearity and hysteretic response in unloading and reloading; and (3) bounding surface plasticity for irrecoverable, anisotropic, and path‐dependent behavior of overconsolidated clays. Model complexity is controlled through the use of input parameters that can be obtained from a small number of standard soil tests. A complete procedure is described to select the input parameters for a given clay. A detailed assessment of the predictive capabilities and limitations of the proposed model is presented in a companion paper.