The load transfer mechanism in pile-supported earth platforms is identified in a series of 3D centrifuge tests. The parametric study includes the influence of the area ratio, proportion of pile area in an elementary mesh, the nature and the level of the load. The preparation and the instrumentation of the models, made of a mixture of sand and clay for the compressible soil, and Hostun sand for the mattress, are detailed. The settlements of the mattress surface are also measured. The results show the effects of the load on the efficiency of the reinforcement system by comparing two area ratios and the two solutions, the floor slab and the landfill.