冰区海上风电基础的抗冰性能分析

摘要

海上风电基础属于典型的柔性结构.由于冰与柔性抗冰结构相互作用的复杂性,长期以来尚未形成基于动冰力响应分析的结构设计.结构抗冰设计中大都是从极端荷载出发,只考虑最大静冰力或最大倾覆力矩.基于对渤海辽东湾柔性抗冰结构的多年监测,发现强烈的冰激振动引起柔性结构的风险性要远大于极端静冰荷载下结构的整体安全问题.为了明确冰区风电基础结构的抗冰性能及抗冰设计的合理性,文章结合基于多年现场冰与结构作用观测及冰荷载的研究成果,明确该类柔性结构与海冰作用形式及其动力特性;提出了柔性抗冰结构设计中应考虑的主要失效模式及评价方法.最后,以渤海某典型风电基础为例,对其抗冰性能进行评价.该文的研究可为寒区风电基础的抗冰设计及安全保障提供合理依据.%The offshore wind turbine foundation belongs to typical slender structure. Due to the complexity of the interaction between ice and ice-resistant slender structure,the structural design based on analysis of the response to dynamic ice force has not been formed for a long time. Most of the ice-resistant structure design is based on the extreme load, only considering the largest static ice force or the maximum negative moment. Based on the many years' monitoring in the Bohai Bay, it was found that the risks of strong ice-induced vibration of flexible structure outweigh the overall security of the structure under extreme static ice load. In order to define the ice resistance of the offshore wind turbine foundation in the ice region and the rationality of the ice-resistant design,in this paper,based on the research results of observation of ice and the interaction between ice and structure, it is clear that the ice load model is suitable for the offshore wind power and the structural dynamic characteristics.And the main failure modes and evaluation methods for the flexible ice-resistant structure design are provided. Finally, the ice-resistant performance is analyzed by tak-ing a new wind turbine foundation in Bohai Sea as an example.This study could provide a reasonable basis on the ice-resist concept design and security assurance for the wind turbine foundations in the cold regions.