An advanced multilaminate model for clay

An advanced constitutive model for clay based on the multilaminate framework for soils is presented. Multilaminate type of models simulate the deformation behaviour of the soil by considering the response on several so-called contact planes. Yield surface and plastic potential are defined individually on these planes. An elasto-plastic constitutive model with shear and volumetric hardening has been formulated in a way suitable for implementation into the multilaminate framework. A non-associated flow rule is implemented for the deviatoric yield surface, whereas associated flow is assumed for the compression yield surface. Because of plastic flow developing independently on the contact planes, initial and induced anisotropy can be accounted for in a straightforward manner. In order to validate the proposed model a number of triaxial stress paths, performed on soft clay, specifically aimed at the determination of the anisotropic behaviour, have been simulated numerically. The results show a good agreement with experimental data although some further enhancements such as modelling destructuration effects may be required to achieve a perfect match of the experiments.