Evaluation of a constitutive model for overconsolidated clays

This Paper evaluates the performance of a generalized effective stress soil model for predicting the rate-independent behaviour of K" normally to moderately overconsolidated clays. The model formulation comprises three components: an elasto-plastic model for normally consolidated clay including anisotropic and strain softening behaviour, equations to describe the small strain non-linearity and hysteretic response in unloading and reloading, and bounding surface plasticity for irrecoverable, anisotropic and path-dependent behaviour of overconsolidated clays. Model complexity is controlled through the use of input parameters which can be obtained from a relatively small number of standard soil tests. The Paper illustrates the selection of model input parameters for a low plasticity, moderately sensitive clay and compares the selected values for different types of clay. Extensive comparisons with measured data from undrained shear tests performed in different modes of shearing and with overconsolidation rati...