單樁式海上風機基頻計算方法及參數分析

摘要： 海上風機結構體系屬于動力敏感型結構，參數變化易對系統基頻產生影響。系統基頻是海上風機結構與基礎設計的關鍵，精確計算系統基頻具有非常重要的工程意義。文章基于Euler-Bernoulli梁理論，考慮樁-土相互作用、水體附加質量和塔筒變截面特性，采用回傳射線矩陣法建立單樁式海上風機系統橫向基頻計算方法。利用實際工程驗證該方法的精確性和有效性，并對系統基頻偏移因素進行綜合分析。分析表明，樁-土相互作用、水體附加質量和塔筒變截面特性對系統基頻影響顯著;系統基頻對參數的敏感性為：樁基埋深gt;樁徑gt;地基土模量gt;上部質量gt;海水深度gt;樁基壁厚;樁基埋深、樁徑、地基土模量和樁基壁厚存在臨界值，超過該值后參數變化對系統基頻基本無影響。文章在一定程度上揭示了系統基頻偏移因素影響規律，可為風機的結構和基礎設計提供參考。

關鍵詞： 海上風機; 單樁基礎; 自振頻率; 水-樁-土相互作用; 參數分析

中圖分類號： TU473""""" 文獻標志碼：A"" 文章編號： 1000-0844（2025）02-0281-08

DOI：10.20000/j.1000-0844.20230720003

Fundamental frequency calculation method and parameter

analysis of monopile offshore wind turbines

YU Yunyan， HOU Haosheng， KONG Jiale

（College of Civil English， Lanzhou Jiaotong University， Lanzhou 730070， Gansu， China）

Abstract：

As a dynamic-sensitive structure， the changes in the offshore wind turbine structure are easy to affect the fundamental frequency of the system. The fundamental frequency of the system is key to the structure and foundation design of offshore wind turbines; hence， it is of great engineering significance to accurately calculate the fundamental frequency of the system. Based on the Euler-Bernoulli beam theory， considering the pile-soil interaction， added water mass， and the variable section characteristics of the tower， a calculation method of the transverse fundamental frequency of the single-pile offshore wind turbine system was established using the reverberation-ray matrix method. The accuracy and effectiveness of the proposed method were verified by a practical project， and the fundamental frequency excursion factors of the system were comprehensively analyzed. The analysis results showed that the pile-soil interaction， the added water mass， and the variable section characteristics of the tower all have a significant effect on the fundamental frequency of the system. The sensitivity of the system's fundamental frequency to different parameters is as follows： buried depth of pile foundation gt; pile diameter gt; modulus of foundation soil gt; upper mass gt; seawater depth gt; wall thickness of pile foundation. When the buried depth of the pile foundation， the pile diameter， the foundation soil modulus， and the wall thickness of the pile foundation exceed the critical value， the change of parameters has little effect on the fundamental frequency of the system. To a certain extent， this paper revealed the influence law of fundamental frequency excursion factors of the system， thus providing a reference for the structure design of offshore wind turbines.

Keywords：

offshore wind turbine; single-pile foundation; natural frequency; water-pile-soil interaction; parameter analysis

0 引言

海上風能分布廣泛、發展潛力巨大，是優質的可再生清潔能源。為解決能源短缺、環境污染等全球性難題，我國在“十四五”期間提出大力發展海上風機這一戰略決策。海上風機的基礎形式豐富多樣，其中單樁基礎因具有結構簡單、占用面積小、承載力高和沉降量小且均勻等優點被廣泛使用，在國外已建工程中占比近80%^［1-2］。我國可根據國外已有設計和施工經驗，大力發展單樁式海上風機，以建設清潔、低碳、安全、高效的現代化能源體系?！?br>