ABSTRACT

To investigate the stability of monopile foundation under dynamic loading, a comprehensive numerical model for the analysis of offshore wind turbines (OWT) foundation under a general transient storm loading is presented in this study. The dynamic stiffness and soil deformation around the large-diameter monopile is simulated using this method. During the numerical analysis, a dynamic boundary surface model of soil is derived instead of the empirical strength degradation. Along the axis direction of the monopile, an intensive study about deformation law of the seabed soil is analysed, moreover, some parameters which may affect the OWT stability and the dynamic stiffness are discussed. Some conclusions can be drawn that the dynamic stiffness and the lateral displacement of the monopile foundation can be obviously improved by increasing the buried depth than the diameter, and the proposed failure mode can well describe the failure law of soil around the monopile due to the dynamic loading.

摘要

为了研究动态荷载下单桩基础的稳定性，本研究提出了一个综合数值模型，用于分析一般瞬态风暴荷载下的海上风力涡轮机（OWT）基础。采用该方法模拟了大直径单桩周围的动刚度和土体变形。在数值分析过程中，推导了土的动态边界面模型，而不是经验强度退化模型。沿单桩轴线方向，深入研究了海底土的变形规律，并讨论了影响OWT稳定性和动力刚度的一些参数。