Numerical modelling of a centrifuged embankment on soft clay

Abstract

Biot coupled consolidation numerical analyses have been applied to a stage-constructed embankment on soft clay in the centrifuge. In the test, the sand embankment was constructed during flight on a clay foundation consisting of an overconsolidated crust overlying a normally consolidated layer. Measurements were taken of pore pressures, dissipation rates, and displacements in the foundation clay. Predictions of these were made using a simple Cam-clay model for the clay and the Cambridge CRISP computer program. A linear elastic idealization was used for the embankment. With some exceptions, pore pressures and dissipation rates were very well predicted, as were maximum values of both horizontal and vertical displacements. However, displacement profiles with depth were not so well predicted. Particular attention is given in the paper to the determination of relevant values of shear modulus G and the difference in behaviour resulting from using constant permeability and permeability varying with void ratio. Key words: embankments, soft clay, centrifuge test, numerical analysis, Biot consolidation, Cam-clay model.