Shaking table dynamic tests of a granular deposit

CEDEX has a six degrees of freedom seismic simulator formed by 3 in long square table, able to move 10 t mass with up to 1-g accelerations. On that simulator a rigid box was placed and filled with some 6 t of Hostun RF sand to study the free field response of a granular deposit subjected to dynamic loading. During the filling of the box, some accelerometers were installed inside the sand to measure accelerations suffered by the granular deposit, and two displacement transducers were placed on the deposit surface. With this equipment, ten tests were conducted in which the sand deposit, with different initial relative densities, was subjected to sinusoidal dynamic loadings, in terms of accelerations, with different amplitudes imposed at the bottom of the box. During those free field tests, accelerations inside the sand and horizontal and vertical movements on the top surface of the granular deposit were measured. The results deduced from the signals recorded by the different accelerometers and from the measurements of vertical and horizontal movements of the sand surface are discussed and compared to real cases and values deduced from theories published in the literature.