Lateral kinematic response of offshore pipe piles to S‐wave seismic excitation

Abstract

AbstractThis paper presents an analytical study on the lateral kinematic response of offshore pipe piles subjected to vertically propagating S‐wave seismic excitation. Both the kinematic interaction of the pipe pile with the soil and seawater are considered. The lateral resistances of the outer and inner soil are obtained based on the confined viscoelastic dynamic continuum models, while the hydrodynamic pressures of the seawater are based on the inviscid incompressible fluid theory. The pile response is then obtained by utilizing the continuity condition at the soil‐pile and seawater‐pile interfaces along the pile shaft. The derived solution is employed to investigate the sensitivity of the seismic response of pipe piles to certain key problem parameters, such as length of pile segment embedded in seawater, the relative stiffness of the pile and soil and the pile radius ratio. We demonstrate that the partially embedded piles are much more flexible compared with fully embedded piles when subjected to S‐wave excitation, resulting more strong motion transferred to the superstructures and the existence of seawater will amplify the seismic responses of offshore pipe piles.