Modelling the rate-sensitive characteristics of the Gloucester foundation soil

Stages 1 (1967) and 2 (1982) of the Gloucester test embankment are studied using a fully coupled finite-element model. The rate-sensitive characterist ics of the foundation soil are modelled using an elastoviscoplastic constit utive equation based on the elliptical cap yield surface and Perzyna's over stress theory of viscoplasticity. The aspect ratio of the yield surface for the Gloucester foundation soil is estimated using conventional laboratory shear and consolidation test results. Calculated and measured behaviour dur ing consolidated isotropically undrained triaxial tests and long-term Rowe cell consolidation tests are compared and the ability of the model to descr ibe the measured behaviour of stages 1 and 2 of the Gloucester test embankm ent is studied. This paper explores the implications of modelling the resid ual or restructured properties of the Gloucester foundation soil and demons trates the ability of a single elastoviscoplastic yield-surface model to de scribe the undrained and drained response of the Gloucester foundation soil during laboratory and field loading conditions.