ABSTRACT
The methods available in the literature for design of column-reinforced soils tend to overestimate the ratio of substitution of in-situ soils. This is confirmed by the difficulty felt on site to incorporate the predicted amount of granular materials. In fact, these methods do not take into account the significant improvement of the surrounding in-situ soils characteristics due to the installation technique and the consolidation process that results from it. Such improvement is largely proved by field control tests.
The prediction of the improvement of the surrounding clay stiffness occurring after vibro-compacted column installation is the purpose of the proposed paper. So, a numerical procedure is carried out to simulate a stone column installation in Leda clay deposit. The simulation is performed by using Sigma W finite element software, the reinforced soil being modelled by a composite cell. A hardening soil model is considered for the clay to take into account the stress-stiffness dependency. The experimental data were analyzed and numerically calibrated for Leda clay using SigmaW. From numerical results it has been predicted both the increase of in-situ soil stiffness and the radius area where this improvement occurred.
