Floating Behavior of a Composite Bucket Foundation under the Combined Action of Wind and Waves

Xing Zhao,Puyang Zhang,Hongyan Ding,Conghuan Le

doi:10.3390/jmse10020147

Abstract

In this study, a composite bucket foundation (CBF) was investigated by taking into account the reflection and refraction effects of waves. A numerical model for the motion responses of the structure under different wave heights and wave periods was built based on the 3D potential flow theory. The model was verified against the test results for analyzing the stability and seakeeping performance of the foundation under the action of waves. Under the combined action of wind and waves, the possible scenarios of floating under wind and waves of different scales and directions were simulated, and the mooring force and motion response peaks and laws of the structure were established, aiming to improve the safety of composite bucket foundation transport and provide technical support for floating construction.

Highlights

Global wind power technology has been greatly developed, and the wind power market has gradually moved towards the development of wind energy at low wind speeds and offshore wind farms
Single-pile foundations, gravity foundations, etc., mostly adopt a step-by-step transportation construction scheme, that is, first use a transport ship to construct the bottom foundation in place, and use auxiliary facilities such as floating cranes to install the upper fan and tower
The floating foundation can adopt a one-step transportation scheme, that is, after the fan, tower, and floating foundation are installed in the shore dock, the whole is transported to the designated location for anchoring by the tugboat

Summary

Introduction

Global wind power technology has been greatly developed, and the wind power market has gradually moved towards the development of wind energy at low wind speeds and offshore wind farms. In 2017, the one-step offshore transport and installation of the foundation, tower, and head of the first 3 MW composite bucket foundation were completed in the Xiangshui Wind Farm of China Three Gorges New Energy Corp. By analyzing the floating simulations that may encounter winds and waves of different levels and directions, the towing force, peak value, and law of motion response of the structure were summarized. It aims to improve the safety of the CBF transportation and provide technical support for a structure’s floating construction

Test Model

Wave Spectrum

Numerical Simulation Conditions

Pitch Angles

Air Pressures

Floating Behavior under the Combined Action of Wind and Waves