粉砂地基中复合筒型基础水平承载特性研究

Horizontal bearing characteristics of composite bucket foundation of offshore wind turbines in silty sand

为揭示粉砂地基中海上风电筒型基础水平承载特性,采用有限元法进行数值建模,并利用离心模型试验结果进行对比验证。研究结果表明:荷载前侧筒壁纵向土压力呈拱形分布,荷载后侧筒壁纵向土压力呈三角形分布,垂直加载时侧筒壁纵向土压力接近静止土压力,且随着荷载的增加,纵向土压力非线性分布愈明显;筒壁径向土压力与cosθ(θ为水平投影平面上计算点与基础中心连线与荷载方向的夹角)呈线性关系,随着荷载的增加,二者间亦逐渐呈非线性变化;随着荷载的增加,基础转动中心向上方和加载方向移动,达到极限承力时,转动中心的深度大致位于筒体底端附近;长径比不影响转动中心的运动规律,且长径比对转动中心竖向位置的影响远大于水平位置。研究结果可为基础结构的优化设计提供参考。

To reveal the horizontal bearing characteristics of composite bucket foundation in silty sand,the finite element software is used in this paper,and the numerical model is verified by the results of centrifugal model test.Main conclusions are as follows:on the front side,the distribution of earth pressure is arched and earth pressure at the bottom is reduced;on the rear side,the earth pressure distribution is roughly triangular,and the earth pressure on the bucket wall in vertical load direction is close to the static earth pressure.There is a linear relationship between the bucket wall earth pressure and cosθ(the angle between the calculation point and the load direction).With the increment of load level,the rotation center of composite bucket foundation moves up and to the load direction,and as the load reaches bearing capacity,the rotation center is located at bucket tip.The aspect ratio of composite bucket foundation does not affect the motion law of the rotation center,and the effect of rotation center on the vertical position of rotation center is obviously greater than that on the horizontal position.The research results provide a reference for optimal structural design of the foundation.