Response of a RC pile behind quay wall to liquefaction-induced lateral spreading: A shake-table investigation

• Behavior of a RC pile foundation behind quay wall prior to and during lateral spreading is presented.
• Lateral soil pressure from lateral spreading soils with a clay crust is proposed.
• A simplified method to predict nonlinear pile response is evaluated.
• Influences of several key factors on inelastic pile behavior are examined.

Response of pile foundations to liquefaction-induced lateral spreading still continues to be a complex problem. A shake-table experiment was carried out to explore the response of a reinforced concrete pile behind a sheet-pile quay wall due to liquefaction-induced lateral soil flow. The quay wall was used to trigger liquefaction-induced large lateral ground deformation. The representative features of the pile and the soil are recorded and analyzed. Particular attention is paid to monotonic lateral pile response. A pressure distribution scenario with a triangular lateral pressure from the non-liquefied crust layer and a uniform lateral pressure from the upper liquefied stratum was proposed. A simplified analytical model based on the classical equation for beam on elastic foundation was adopted to evaluate nonlinear behavior of the pile. On this basis, the model was calibrated to represent the experimental observations. Then, key parameters influencing nonlinear pile response were determined. The simulations demonstrated that the model underestimates lateral pile deformation and negligibly influences the moments when linear pile behavior was assumed. Larger pile diameter while holding a constant stiffness could greatly increase the moments and displacements of the pile. Nevertheless, the axial force from the superstructure has a tendency to increase the pile responses to a certain extent. This study further enhances the current understanding of the pile behavior under lateral spreading. Finally, additional large-scale experimental studies are needed in order to provide more data for calibration of soil flow pressure and evaluate inelastic response of piles due to lateral spreading of liquefied soils.