Comparison of Numerical Analyses of Behaviour of Column-Reinforced Foundations

Abstract

This paper studies the prediction of behaviour of foundations resting on a soil reinforced by sand and stone columns. The preliminary design is based on an optimized improvement area ratio predicted by the methodology proposed by Bouassida & Carter (2014). The prediction of the behaviour of the reinforced soil is predicted by numerical computations carried out by Plaxis V9.2D and FLAC3D codes in plane strain and axisymmetric conditions. A Tunisian case history of oil tank is investigated. When assuming the linear elastic behaviour for constituents of reinforced soil, it is noted that the predictions of settlements given by Columns 1.01 software are in good agreement with numerical results obtained by Plaxis and FLAC3D codes. Comparison between those approaches shows the validity of results using the Columns 1.01 software. By adopting the Mohr-Coulomb failure criterion for columns material and the hardening soil model for soft clay, the evolution of long term settlement predicted by Plaxis code showed the acceleration of the consolidation of the compressible soft clay due to the enhanced drainage property of column material.