Dynamic flexural buckling for circular tube plies based on centrifuge tests of superstruecture-pile-liquefied soil system

The steel piles beneath the building structures may buckle when the soil becomes liquefied during the large earthquake. In our previous papers, the static buckling behavior of the steel pile is clarified, but the shaking tests of the frames with circular tube piles and the soil, has not been performed to clarify the dynamic buckling behavior. In this paper, the centrifuge test which is a kind of the shaking tests, is applied for the dynamic behavior of small scaled models with the similarity rule, and it is shown that the collapse mechanism issued from dynamic flexural buckling for the piles in liquefied soil is described, and the piles' strength with liquefied soil is larger than that without soil because of the subgrade reaction.