Influences of Pile Group Effects on Wave Forces on an Offshore Bridge Pile-Cap Foundation

Abstract

In this study, a three-dimensional numerical model for a pile-cap system of an offshore bridge is developed to examine the pile group effect on wave force of pile with different arrangements of the pile group with a pile-cap system. In the present model, the Reynolds-averaged Navier-Stokes equation is taken as the governing equation for wave motion, while the volume of fluid method is used to trace the free water surface. Based on the present model, a set of analysis was conducted to examine the influence of the pile-cap system on the pile group effect, including the arrangement of the pile group, the submerged depth of the bridge cap, and the existence of the cap. Numerical examples show that the present model overall agreed well with the previous experimental data. The existence of the cap and submerged coefficient of the cap have a significant influence on the pile group effect coefficient. During the study of the pile group effect on the wave force of a pile with a pile-cap system of an offshore bridge, the influence of the existence of the cap on the pile group effect needs to be considered.

Keywords

• pile group effect
• wave forces
• pile-cap system
• offshore bridge