Numerical Study of Horizontal Wave Load on Composite Pile Foundation in Marine Environment

To investigate the effects of pile cap submerged depth and wave obliquity on wave load on a composite pile foundation, a three-dimensional numerical model for wave-structure interaction around the Pingtan Strait railway bridge foundation was established. This model was based on the CFD code FLOW-3D, in which the Reynolds-averaged Navier-Stokes (RANS) equation and k-ε turbulence model are used for wave simulations. After validating by analytical solutions and previous laboratory experiments, the model was used to study the effects of pile cap submerged depth and wave obliquity on wave load on the composite foundation. The numerical results indicate that the pile cap submerged depth can significantly affect the wave load on the composite pile foundation, and the wave load on the pile foundation is maximum when the submerged depth is approximately 1 times the pile cap thickness. In addition, the horizontal wave load on the composite foundation increases with the increment of wave incidence angle when the incidence wave angle is defined as the angle between the long axis of the cap and the wave propagation direction. When the wave incidence angle is 90°, the wave load on the foundation is approximately 1.4 times that with a wave incidence angle of 0°.