Secondary compression of clays as a local dehydration process

Abstract

Long-term volumetric deformations of clays are interpreted in terms of water transfer from clay aggregates to the bulk water. Chemical potentials for the two states of water are first derived and then integrated into balance equations in order to find expressions for the rate of secondary deformation. The resulting model requires the determination of three material parameters, which have a physical interpretation. A procedure to interpret conventional consolidation tests and to find model parameters is described. The model seems to capture well the observed features of secondary clay behaviour, and reproduces in a consistent manner the response of samples of different thickness.