Shaking Table Tests On Shallow Foundations
Free (open access)
J. Estaire & V. Cuéllar
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. Keywords: model test, shallow foundations, earthquake resistant, sand, settlement. 1 Introduction Earthquakes are still nowadays natural phenomena of a great destructive potential, so there is a great interest in achieving a better knowledge of the behaviour of soils and the structures founded on them under dynamic conditions. Shallow foundations have had a seismic behaviour that can be qualified as good and adequate, so they have not received much attention in the past. However, failure cases reported in some buildings in Ciudad de Mexico, founded on soft clay, during the Michoacán earthquake in 1985, Romo and Auvinet ,
model test, shallow foundations, earthquake resistant, sand, settlement.