Liquefaction-induced large displacement of pile-supported wharf

Centrifuge model tests were carried out to investigate the dynamic behaviour of a pile-supported wharf in front of backfilled gravity type caissons, focusing on the failure mechanism of the piles, the effects of liquefaction in the backfill and underlying sand layer on the permanent deformation of the wharf during earthquakes, and the dynamic interaction between the piled deck and caisson through the approach bridge. The targeted piled structure is the pile-supported wharf damaged in the 1995 Hyogo-ken Nambu Earthquake at Takahama, Kobe. Centrifuge model tests reasonably predicted the failure mode of the piled wharf observed in the Kobe Earthquake. In parametric study, varying the thickness of the sand layer under the rubble mound caused a change of the deformation mode of both ground and structures and it is revealed that a thicker liquefiable sand layer does not necessarily cause a larger deformation of soil and the structures.