ABSTRACT
Constitutive models are developed in soil mechanics in the framework of continuum mechanics to help predicting the behaviour of large geo-structures. These models are developed on the bases of triaxial or biaxial laboratory tests, which are supposed to represent the macroscopic behaviour. This is why specific care regarding the sample size and aspect ratio (e.g. ratio of the height to the diameter or the width) has to be taken and why antifretting systems have to be employed. In particular the sample has to be large enough to include a sufficient number of grains to ensure that the sample is a “Representative Elementary Volume” of the equivalent continuous material.
