A Novel Elasto-Thermo-Viscoplastic Model for the Isotropic Compression of Structured Clays

Abstract

In many engineering applications, structured clay layers may be subjected to long-term loading and temperature variations. Review of the technical literature reveals that there are a number of constitutive models that deal individually with structure, creep deformations, and temperature changes, or with two of these three phenomena combined. In the present study, a new constitutive model is proposed that consider all three factors simultaneously. The model has been developed based on the variations of the location of the normal consolidation line (NCL) in the compression plane (e − ln p′) due to structuring, rate of loading, and temperature. The formulation of a model was derived for each part separately and then, due to the paucity of experimental data, overall effects were assembled without considering any interaction between them. The model requires 14 parameters with clear physical or mechanical meaning that can be determined in a straightforward way. In spite of the limited experimental information on the effects of all three factors operating together, simulations of the behavior of some available tests confirm the ability of the model to incorporate the influence of those factors on the behavior of Boom clay.