A hypoplastic constitutive model for clays with meta-stable structure

Abstract

A new hypoplastic model for clays with meta-stable structure is presented in this paper. A new method for incorporation of structure effects into hypoplastic models based on the modification of barotropy and pyknotropy factors is proposed and applied to an existing hypoplastic model for reconstituted clays. The new model is characterized by a simple calibration procedure and a small number of parameters. This makes the model particularly suitable for practical applications. The model is evaluated using experimental data for two natural soft clays. Thanks to the incrementally nonlinear character of the hypoplastic equation, the proposed model predicts behaviour of overconsolidated clays comparably to advanced kinematic hardening elastoplastic models.Key words: constitutive relations, hypoplasticity, clays, structure of soils.