Numerical study for wave-induced seabed response around offshore wind turbine foundation in Donghai offshore wind farm, Shanghai, China

Abstract

Analysis of the wave-seabed-structure interaction is of great importance for the design and construction of marine structures. In this paper, a three-dimensional porous model, based on Reynolds-Averaged Navier-Stokes equations and Biot?s poro-elastic theory, is developed by integrating 3D wave and seabed models to simulate the wave-seabed-structure interaction around the high-rising structure foundation used in the Donghai offshore wind farm. Then parametric studies for wave and seabed characteristics on soil response around the wind turbine foundation are conducted. Liquefaction potential and seabed protection methodology are investigated in the last section. The main results concluded from the numerical analysis are as follows: (i) both larger wave height and longer wave period will result in higher wave pressure on the structure and seabed; (ii) the existence of the structure has a significant effect on the wave transformation and the distribution of wave-induced pore pressure; (iii) wave height, wave period, soil permeability and degree of saturation play critical roles on dynamic soil behavior; and (iv) original seabed can be protected from liquefaction by replacing the existing layers.