Liu Junwei, Wan Zhipeng, Dai Xingke, Jeng Dongsheng, Zhao Yanping
College of Architecture and Civil Engineering, Qingdao University of Technology, Qingdao 266033, China.
School of Engineering and Built Environment, Griffith University, Gold Coast Campus, Southport QLD 4222, Australia.
Sensors (Basel). 2020 Sep 18;20(18):5348. doi: 10.3390/s20185348.
The offshore wind energy (OWE) pile foundation is mainly a large diameter open-ended single pile in shallow water, which has to bear long-term horizontal cyclic loads such as wind and waves during OWE project lifetime. Under the complex cyclic loads, the stress and displacement fields of the pile-soil system change continuously, which affects the dynamic characteristics of the pile foundation. Within the service life of the pile foundation, the pile-soil system has irreversible cumulative deformation, which further causes damage to the whole structure. Therefore, it is important to examine the overall dynamic characteristics of wind power foundation under high cycle. In this paper, in the dry sand foundation, taking the Burbo Bank 3.6 MW offshore turbine-foundation structure as the prototype, the horizontal cyclic loading model tests of the wind power pile foundation with the scale of 1:50 were carried out. Considering the factors such as loading frequency and cyclic load ratio, the horizontal dynamic characteristics of the whole OWE pile foundation are studied. The comparison results between the maximum bending moment of pile and the fitting formula are discussed. In conclusion, moment of OWE pile shaft is corresponding to the loading frequency ( = 9 HZ) and loading cycles by fitting formulas. The fatigue damage of the OWE pile does not occurs with low frequencies in high cycles.
海上风电桩基在浅水区主要为大直径开口单桩，在海上风电项目寿命期内，该桩基必须承受风浪等长期水平循环荷载。在复杂循环荷载作用下，桩 - 土系统的应力和位移场不断变化，进而影响桩基的动力特性。在桩基使用寿命内，桩 - 土系统存在不可逆的累积变形，这会进一步对整个结构造成损伤。因此，研究高周循环下风电基础的整体动力特性具有重要意义。本文在干砂地基中，以伯博银行3.6兆瓦海上风机基础结构为原型，开展了比例为1:50的风电桩基水平循环加载模型试验。考虑加载频率、循环荷载比等因素，研究了整个海上风电桩基的水平动力特性。探讨了桩身最大弯矩与拟合公式的对比结果。研究得出，通过拟合公式可知，海上风电桩身弯矩与加载频率（=9赫兹）及加载循环次数相对应。在高循环次数下，低频时海上风电桩不会发生疲劳损伤。
