Reproduction of Lateral Ground Displacements and Lateral-Flow Earth Pressures Acting on Pile Foundations Using Centrifuge Modeling

Dynamic centrifuge model tests were conducted to simulate the seismically-induced displacements of sheet pile quay walls, in order to understand the mechanisms of lateral ground flow of liquefied soil and to evaluate the effects of the lateral-flow earth pressures acting on pile foundations. Two wall-structure-soil model systems were prepared in a laminar container with the inner dimensions of 31.5cm in the height, 47.5cm in the width and 80cm in the length. Shaking table tests were performed under a centrifuge acceleration of 30 g. The first model was designed to simulate the lateral ground flow displacements both during shakings and post liquefaction on sand ground behind a sheet pile quay wall. The second model was designed to measure lateral-flow earth pressures acting on pile foundations against lateral ground flow that probably occurs due to induced lateral movement of the sheet pile wall. It was found that the tests could virtually reproduce the actual lateral-flow of ground caused both during shakings and post liquefaction; the influence of shaking acceleration was very large for the residual displacement of pile foundations; the lateral-flow earth pressures acting on foundations were considerably smaller than the value calculated in the Specifications for Highway Bridges