With the use of numerical modelling, engineers aim to obtain the displacement fields as well as the stress values (effective stress, pore pressure and suction) in the road and earthworks sub-structure. The numerical modelling allows the understanding of the behaviour of the geostructure and the analysis of an optimal design. In order to be successful, the computational tool should, then, include the main physical processes of the rheology of the materials that make up the structure.
The behaviour of granular media is mainly dependant on an inter-granular friction as well as on the applied stress which modifies the rigidity and the strength of the material. It is highly non-linear and irreversible. Figure 9.2 summarizes the main stress-strain aspects.
Fig. 9.2 The main stress-strain aspects of a granular medium
