Numerical analysis of a road embankment constructed on soft clay stabilized with stone columns

A new constitutive law for describing the behaviour of stone column reinforced clay is applied to the analysis of a road embankment constructed on soft clay stabilized by gravel piles. In this model the influence of the columns is assumed to be uniformly distributed over the reinforced region i.e. the constitutive law is formulated for an equivalent material consisting of gravel and clay. It combines the Mohr-Coulomb failure criterion and the Critical State model to represent the elasto-plastic behaviour of gravel and clay respectively. The compaction of the clay due to the installation process of the columns is taken into account by a simple approximation. The model has been implemented into a finite element code and it is emphasized that the finite element mesh is independent of column spacing and diameter thus parametric studies to determine optimum spacing are carried out very efficiently.