基于HSS模型海上风电桶形基础水平循环承载特性对比研究  

Comparative study on horizontal cyclic bearing characteristics of offshore wind turbine bucket foundations based on HSS model

作　　者：寇海磊[1] 房伟伟 徐祥程 安兆暾 张洪睿 KOU Hailei;FANG Weiwei;XU Xiangcheng;AN Zhaotun;ZHANG Hongrui(College of Engineering,Ocean University of China,Qingdao 266500,China)

机构地区：[1]中国海洋大学工程学院,山东青岛266500

出　　处：《海洋工程》2024年第4期1-12,共12页The Ocean Engineering

基　　金：山东省泰山学者青年专家项目(tsqn202306098);国家自然科学基金资助项目(51879246)。

摘　　要：采用土体本构模型对黏土中的桶形基础进行了有限元模拟,以研究桶形基础的水平循环承载特性。利用有限元方法模拟了在不同单调组合荷载作用下黏土中的桶形基础离心机试验,与试验结果对比验证了使用小应变硬化土(HSS)本构模型的适用性。在此基础上,基于HSS模型和硬化土(HS)模型对比研究了不同循环荷载和小应变模量对桶形基础累积转角、旋转中心和桶-土相对刚度的影响。结果表明,黏土中桶形基础的累积转角随着循环次数和水平荷载的增加而增加,然而每个循环中累积转角的增加逐渐减小。另外,提出了Tb和ζb之间的拟合关系式预测黏土中桶形基础的累积旋转。无论处于疲劳极限状态(ζb=0.3)还是正常使用极限状态(ζb=0.5),旋转中心类型都是从深中心变为浅中心。桶-土相对刚度随循环次数的增加而减小,并且循环荷载越大刚度衰减越大。另外,小应变模量对基础累积转角和桶-土相对刚度有较大影响而对旋转中心无显著影响。与已有的研究结果对比发现,HSS模型更加适用于精细化设计。Finite element simulations of bucket foundations in clay using soil constitutive models were conducted to investigate the horizontal cyclic bearing characteristics of bucket foundations.Centrifuge tests of bucket foundations in clay under different monotonic combined loads were simulated using the finite element method to validate the applicability of the small strain hardening soil(HSS)constitutive model.Based on the HSS model and HS model,the effects of different cyclic loads and small strain modulus on the accumulated rotation angle,rotation center,and bucket-soil relative stiffness of bucket foundations were compared.The results indicate that the accumulated rotation angle of bucket foundations in clay increases with the number of cycles and the increase of horizontal loads.However,the increase in accumulated rotation angle per cycle gradually decreases.Furthermore,an empirical equation between T_(b) and ζ_(b) is proposed to predict the cumulative rotation of bucket foundation in clay.Regardless of being in a fatigue limit state(ζ_(b)=0.3)or a normal operating limit state(ζ_(b)=0.5),the rotation center type changes from deep center to shallow center.The bucket-soil relative stiffness decreases with the number of cycles,and the greater the cyclic load,the greater the stiffness decay.In addition,the small strain modulus has a significant influence on the accumulated rotation angle and bucket-soil relative stiffness,but no significant influence on the rotation center.Comparing with existing research results,it is found that the HSS model is more suitable for refined design.

关 键 词：海上风电 桶形基础 水平循环荷载 HSS模型 累积转角 旋转中心 桶-土相对刚度 

分 类 号：P751[交通运输工程—港口、海岸及近海工程] TU473.1[天文地球—海洋科学]