海上风电基础除承受复杂组合荷载作用外,也受波流冲刷作用.为探讨局部冲刷对砂土地基中V-H联合加载下单桩-摩擦盘复合基础承载特性的影响,基于自行设计的室内水槽试验装置,完成了一系列冲刷及模型载荷试验,获得了复合基础冲刷前后的荷载-位移曲线,经无量纲化处理与曲线拟合,得到复合基础承载包络线及其简化计算公式.计算结果表明:局部冲刷作用使复合基础的竖向及横向抗力明显降低,削弱程度分别约12.1%和26.9%.进一步分析表明:存在一个最优预加竖向荷载(V),其对复合基础的极限横向承载力起到最显著的增强效果;此外,局部冲刷作用导致V-H联合受荷单桩-摩擦盘复合基础的承载包络线明显向内收缩,所提出的简化计算公式可供工程应用参考.
The foundations of offshore wind turbines(OWTs)are often subjected not only to complex combination loads, but also subjected to the local scouring. To investigate the effects of the local scouring on the bearing characteristics of the monopile-friction wheel composite foundations under combined V-H loads, a series of indoor model tests are carried out based on indoor water tank test devices. The load-displacement curves are obtained for the composite foundations with and without scouring. After dimensionless treatment and curve fitting process, the envelopes of the bearing capacities and the corresponding simplified formulas are also obtained. The results show that: the vertical and horizontal bearing capacity of the composite foundation can be reduced by about 12.1% and 26.9%, respectively. Further analysis shows that there exists an optimal pre-vertical load(V)which significantly enhances the ultimate lateral bearing capacity of the composite foundation. Additionally, the envelope shrinks inward under scouring conditions. The proposed empirical formulas can be used as a reference for engineering practice.
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