在40~60 m水深海域,海上风力发电机多使用导管架基础作为主要支撑结构.导管架通过水下高强灌浆与桩基础顶部连接,形成顶端密封段,共同承载竖向荷载.针对桩基顶部灌浆正常、灌浆不足、灌浆不良存在通孔3种不同灌浆效果开展离心模型试验,分析极限状态下基础的竖向承载力及灌浆段与桩身段的承载力分担比,并与现有理论计算方法进行对比.结果表明,灌浆密封顶盖的承载力取决于密封效果.对于灌浆密封顶盖灌浆正常和灌浆不足的基础,灌浆密封顶盖的承载力约占基础总承载力的25%~30%;灌浆不良存在通孔时,基础灌浆段承载力发挥较早且很快达到极限,其分担比远低于其他两者承载力.试验结果可为导管架桩基础设计中的灌浆段承载力计算提供参考依据.

Jacket foundations are often used as the main support structure for offshore wind turbines in waters with a depth of 40—60 meters. The jacket foundation is connected to the top of the pile foundation through underwater high-strength grouting to form a top sealing section, which together bears the vertical load. In this paper, centrifugal model tests are conducted for three different grouting effects: normal grouting at the top of a pile foundation, insufficient grouting, and poor grouting with through-holes. The vertical bearing capacity of the foundation and the bearing capacity sharing ratio between the grouting section and the pile body section under the limit state are analyzed, and compared with existing theoretical calculation methods. The results show that the bearing capacity of the grouting sealing cap depends on the sealing effect. For foundations with normal grouting and insufficient grouting of grouting sealing caps, the bearing capacity of grouting sealing caps accounts for approximately 25%—30% of the total bearing capacity of the foundation. When there are through-holes in poor grouting, the bearing capacity of the foundation grouting section develops early and quickly reaches its limit, whose sharing ratio is far lower than the other two bearing capacities. The test results in this paper can provide a reference for the calculation of bearing capacity in foundation design.