Behaviour of model pile foundations under dynamic loads in saturated sand

In Japan and Turkey, predominantly traditional design concept of pile group is still adopted even though most pile foundations are piled raft foundations in reality. This situation may be attributed to the still limited knowledge about behaviour of piled rafts subjected to the combination of static and dynamic loads. Hence, in this study, a series of shaking table tests on 3-pile piled raft and 3-pile pile group models were carried out in saturated sand at 1-g field under the combinations of static vertical and dynamic horizontal loading, where the input motion was sinusoidal wave having a frequency of 20 Hz and 1.50 and 6.00 m/s2 amplitudes. The results showed that, raft-model ground contact in piled raft is very effective to reduce settlement compared to pile group even in liquefied soil. Moreover, even in piled raft, the horizontal resistance reduces if liquefaction of the ground surface occurs, due to the loss of the raft base resistance.