Geotechnical fragility analysis of monopile foundations for offshore wind turbines in extreme storms
Geotechnical fragility analysis of monopile foundations for offshore wind turbines in extreme storms
复制标题
DOI：
10.1016/j.renene.2021.10.092
复制
发表时间：
2021-11
期刊：
影响因子：
8.7
通讯作者：
T. Charlton;M. Rouainia
中科院分区：
文献类型：
--
作者：
T. Charlton;M. Rouainia
海上风力涡轮机（OWT）必须在其20至30年的设计寿命内承受恶劣的环境载荷。脆弱性分析研究了在一定灾害强度范围内的损坏概率，是基于性能的工程方法的组成部分。本文的重点是锚桩，这是广泛用于支持OWT在水深约40米。本文提出了一个脆弱性分析的极端风暴中的土工性能，衡量永久旋转的基础。由于预测循环荷载下土壤特性和估计极端响应概率的挑战，岩土脆弱性迄今尚未得到全面解决。在后者，本文开发了有效的Karhunen-Loeve表示的风和波浪载荷，可以结合廉价的概率方法来计算脆弱性。该框架是使用一个有代表性的情况下，5兆瓦的OWT安装在粘土。非线性的基础响应被捕获的动态三维有限元模型。脆弱性曲线生成使用子集模拟风暴重现期（RP）从1到100年。在极端风暴（与50年和100年的RP）的脆弱性显着高于风暴的RP为10年或更少。
Offshore wind turbines (OWTs) must withstand harsh environmental loads over their 20- to 30-year design life. Fragility analysis investigates the probability of damage over a range of hazard intensities and is integral to a performance-based engineering approach. The focus of this paper is on monopiles, which are widely used to support OWTs in water depths up to around 40m. The paper presents a fragility analysis of monopiles in extreme storms in terms of geotechnical performance, measured by permanent rotation of the foundation. Geotechnical fragility has so far not been comprehensively addressed due to the challenge of predicting soil behaviour under cyclic loading and estimating the probability of extreme responses. On the latter, the paper develops efficient Karhunen-Loeve representations of wind and wave loading that can be combined with inexpensive probabilistic methods to compute fragility. The framework was demonstrated using a representative scenario of a 5 MW OWT installed in clay. Non-linear foundation response was captured by a dynamic 3D finite element model. Fragility curves were generated using subset simulation for storms with return periods (RPs) from 1 to 100 years. Fragility during extreme storms (with 50- and 100-year RPs) was significantly higher than storms with RPs of 10 years or less.