The effect of structural stiffness on the efficiency of seismic base isolation using layers of stone pebbles is experimentally investigated by shake-table. The efficiency of the adopted layers is tested on four models with different stiffness, under four different earthquake accelerograms. A part of the study was carried out for one-time accelerations of the shake-table with strains in elastic range, and another part, for the most unfavourable accelerogram, was carried out by successive increase in the acceleration to the collapse of the model. It is concluded that efficiency of the considered seismic isolations systems decreased with decrease of model stiffness and that this concept shows great potential in increase of structural seismic resistance.
