On the modelling of anisotropy and destructuration of soft clays within the multi-laminate framework

Abstract

The possibilities and limitations of modelling the behaviour of soft natural clays within the multi-laminate framework are discussed in this paper. The presented version of the constitutive model was developed to describe two important characteristics of the soft clay behaviour: strength anisotropy and destructuration. Viscous effects are not taken into account. Strength anisotropy of the soft clay is achieved using the multi-laminate model with controlled spatial distribution of the preconsolidation pressure over the sampling planes. This spatial distribution is related to the initial stress state and is additionally adjusted by the distribution of bonding. Bonding or structural anisotropy is not permanent in the model and may be reduced during the process of destructuration. Interrelation between stress-induced and bonding anisotropy is shown by investigating the shape changes of a macro yield surface resulting from the multi-laminate modelling. Performance of the new model is demonstrated by standard element tests and also by the boundary value problem of an embankment on soft ground.