淤泥质黏土中复合筒型基础水平承载力试验研究

Model tests on bearing capacity of composite bucket foundation in clay

复合筒型基础作为一种新型海上风力发电基础,与以往的筒型基础结构形式有较大差别,其极限承载能力及筒土作用机理需进一步深入研究。针对这一问题,设计了复合筒型基础大尺寸模型,开展了淤泥质黏土中的水平承载力试验,得到了复合筒型基础在水平荷载作用下的土压力分布规律、位移变化机制及极限承载能力等。试验结果表明,随着荷载的增加,被动区土压力有较大增长,主动区土压力呈现负压并逐渐恢复为初始土压力;旋转中心的位置随着荷载的增加从中轴线附近逐渐沿着加载方向移动,极限荷载时,旋转中心位于距顶面0.8倍筒壁高度处的分仓板附近。

As a new type of offshore wind power foundation, the composite bucket foundation has large difference in structural form from the traditional bucket foundation, thus its ultimate bearing capacity and bucket-soil interaction mechanism need timber research. Aiming at this problem, a large-size model for the composite bucket foundation is designed, and several horizontal bearing capacity tests are carried out in clay. The distribution of soil pressure, the motion mechanism and the ultimate bearing capacity of the composite bucket foundation are determined depending on the tests. The test results show that the soil pressure on the passive zone increases significantly with the increase of horizontal load, while the soil pressure on the active zone has negative growth at first and returns to the initial value finally. The position of the instantaneous rotation center moves from the central axis to the bottom of the bulkhead at the loading direction with the increase of horizontal load, and it＇s approximately 0.8L below the ground surface around the bulkhead at the loading direction under the ultimate horizontal load.