Shaking table tests on shallow foundations

Abstract

In this paper the results of shaking table tests on shallow foundations, using dry Hostun RF sand, are presented. These tests were performed in a six-degree of freedom seismic simulator formed by 3 m long square table, able to move 10 t mass with up to 1-g accelerations. On that simulator a rigid box of great dimensions (3 m long, 1,1 m wide and 1,2 m high) was placed and filled with some 6 t of sand. During the filling of the box, some accelerometers were installed inside the sand to measure accelerations suffered by the granular deposit. The shallow foundations were modelled with three metallic blocks that transmitted different loads to the ground. The tests were designed taking into account the usual scale factors. In the thirty tests performed, the shaking table imposed a wavy acceleration at the bottom of the box with different amplitudes and frequencies. The result analysis was focused on the amplification of acceleration during its propagation in vertical direction through the sand deposit and the vertical and horizontal movements of the foundation blocks during the dynamic excitation.