40 / 2025-04-24 12:55:02

Centrifuge experiments on submarine gravity flow of liquefied sand and its impact on structures

This study examines the behavior of submarine gravity flows of liquefied sand and their impact
on subsea structures through centrifuge model tests. The centrifuge model testing technique
provides an effective method for simulating submarine gravity flows, reproducing prototype
scale conditions under enhanced gravities. A sediment gravity flow with a velocity of 2.5 m/s,
generated by the liquefaction of a 5 m-thick sand bed on the prototype scale was successfully
reproduced in the drum centrifuge channel under a centrifuge acceleration of 50g. The impact
pressures of the sediment gravity flow on the structures placed on the channel floor were
measured. It was found that when the sediment gravity flow head reached the structure, the
pressure on the structure rapidly increased, and then remained at a high level followed by a
gradual decrease in the impact pressures. The pressure exerted on the structures was found to be
approximately twice that of the pressure acting on the channel floor. This suggests that
embedding structures in the seabed can substantially reduce impact pressures compared to those
when placing them on the seabed surface.