DYNAMIC BEHAVIOUR OF SOILS REINFORCED BY RIGID INCLUSIONS. SMALL SCALE EXPERIMENT AND NUMERICAL MODELLING.

Soft soils used as foundation support require special attention, especially when high load structures are built. Traditional solutions include either replacement or pile foundations, both onerous. Improvement is also a possibility and here can be cited the improvement by rigid inclusions. This technique is used for foundations on soft soils of large engineering works (bridges, wind farms, industrial platforms etc.) in safe conditions and with low cost. The method combines the inclusions in form of piles, soil-mixing columns or other and a granular load transfer platform. If the static behaviour of such systems has been extensively studied these last years, it is not the same for the dynamic one. Paper presents briefly the technique and its applications and the validation and calibration of a 3D numerical model based on experimental tests performed on shaking table on a small-scale equivalent model. The calibration was made for the first mode of vibration and for an elastic behaviour of used materials, taking into account both frequencies and displacements. Also, comparisons between numerical and theoretical methods (homogenization method) are presented. Thus, resulted a 3D model which can be further used for more deep analyses on the dynamic behaviour of soils reinforced by rigid inclusions.