Dynamic Centrifuge Modeling of Liquefaction-Induced Buckling Instability in Pile During Earthquake

Abstract

Pile foundations are the most widely used form of deep foundations to support both vertical and horizontal loads in geotechnical projects. Regarding the earthquake, pile foundation may lose their lateral resistance in the liquefied ground, which could cause critical economic losses and lead to severe consequences. Although research has been done on the buckling of pile foundations, there are still many observations on the structural failure of pile foundations in past earthquakes. It is essential to understand the behavior of the foundations under such conditions. In this paper, a series of centrifuge tests under different vertical loading conditions and ground conditions were performed to investigate the mechanism of buckling failure of piles. It was observed that the end-bearing single piles resting on a rigid layer can buckle under the effect of axial load and horizontal inertial load during earthquake-induced liquefaction. The failure type observed in the tests probably is the P-Δ failure, which is highly related to geometric nonlinearity. Under large axial loads, the relatively small lateral load will have a great influence on the capacity of the foundation. The pile foundations in the tests collapsed from 25 s to 265 s after the end of the shaking process (the duration of the shaking is 20 s). Besides, the soil layers offered considerable support to the piles even when the excess pore water pressure didn’t dissipate completely.