上覆软土层对海上风电四筒基础承载特性影响

Effect of overlying soft soil layer on bearing capacity of four bucket foundation for offshore wind turbines

为研究上覆软土层对海上风机宽浅式四筒基础承载特性的影响,采用ABAQUS有限元软件建立了宽浅式四筒基础模型,选取砂土和上覆不同厚度软土层为地基,对基础单向荷载作用下的承载能力、基础破坏特征和竖向荷载、水平荷载及弯矩作用下的筒侧土压力进行了研究。研究发现:单向荷载作用下海上风机宽浅式四筒基础承载力随上覆软土层厚度增加而线性降低。软土层使土体塑性破坏区域范围缩小且下移,但对转动中心位置无影响。上覆软土层使竖向荷载作用下筒顶土压力更加均匀,水平荷载和弯矩作用下筒侧面被动土压力在承载中具有重要作用,但随上覆软土层厚度增加而降低。

To investigate the effect of overlying soft soil layer on the bearing capacity of the wide-shallow four bucket foundation for offshore wind turbines,a model was established by ABAQUS FEM software.The bearing capacity,failure characteristics under unidirectional load and the lateral earth pressure under vertical load,horizontal load,and bending moment were studied in sandy soil with different thickness of soft soil.The results show that the bearing capacity of the wide-shallow four bucket foundation decreases linearly with the increase of the overlying soft soil thickness under unidirectional load.Affected by the soft soil layer,the plastic collapse area of the soil decreases and moves down,but the center of rotation is unchanged;the soil pressure at the top of the bucket is more uniform under the vertical load;the lateral passive earth pressure under horizontal load and bending moment is important to the bearing capacity,but it decreases with the increase of the thickness of the overlying soft soil layer.