导管架基础海上风机动力响应数值分析

针对导管架基础海上风机（OWTs），开展台风极端循环荷载下整体结构的动力响应数值计算与分析. 在数值计算中分别采用美国石油学会（API）规范的系列桩-土相互作用模型（p-y、t-z、Q-z）、可考虑桩-土界面竖向强度和刚度循环弱化效应的弹塑性t-z模型以及桩-土侧向弹塑性p-y模型. 数值研究结果表明，t-z弹簧对导管架基础海上风机泥面处抗倾覆弯矩的贡献最大；p-y弹簧的贡献可能为负，其主要作用为抵抗水平力；Q-z弹簧的贡献较小，可忽略不计. 考虑t-z弹簧的循环弱化效应会大大增加基础顶点处的转角响应；考虑t-z、p-y弹簧循环弱化耦合作用，导管架基础的平动更为明显，基础顶点处的位移响应明显增大. 在工程设计中须对桩-土循环弱化效应予以充分考虑.

Numerical analysis of dynamic responses of jacket supported offshore wind turbines

For jacket supported offshore wind turbines (OWTs), numerical calculations and analysis were performed to investigate the dynamic responses of the whole structures under extreme cyclic loadings of typhoon condition. The series of pile-soil interaction models (p-y, t-z, Q-z) in the code of American Petroleum Institute (API), an elastoplastic t-z model considering the cyclic degradation of strength and stiffness axially in the pile-soil interface as well as an elastoplastic p-y model representing the lateral behaviors were used in the numerical simulations. Results show that the largest proportion of the anti-overturning moment at the mudline of jacket supported OWT is provided by the t-z spring. A negative contribution to the anti-overturning moment may be caused by the p-y spring, and the main function of p-y spring is to resist the horizontal loadings. The contribution from the Q-z spring is small and negligible. The rotation response at the top of jacket foundation may increase obviously with the consideration of the cyclic degradation effect of t-z spring. Considering the coupling degradation effects of the t-z and p-y springs, the translation of the jacket foundation will be more obvious and the displacement response at the top of the foundation will increase significantly. Thus the effects of the pile-soil cyclic degradation should be considered adequately in the engineering design.