Effects of cyclic axial loading sequences on piles in sand

The cyclic axial behaviour of piled foundations in sand is studied using centrifuge tests. Model piles are partially jacked in flight. Loads are applied to identify cyclic tension loading effects in stable and meta-stable zones on pile behaviour and physical failure. Failure occurs with larger displacements than those achieved during monotonic loading tests. Sequences of 200 cycles with three different amplitudes are applied in different orders. With the same total amount of cycles, final displacements are different and potentially lead to failure. The order of the cyclic sequences significantly affects pile behaviour; however, this is not taken into account or even mentioned in standards.