摘要
针对最近提出的锚杆重力式海上风机基础,采用有限元分析软件ABAQUS研究了锚杆的关键参数对此新型基础承载特性的影响。结果表明:增加锚杆数量可以提高基础的承载力并减小单根锚杆的轴力。但是当锚杆数量增加到一定程度时,会使其间距过小,引起地基中应力的叠加,降低锚杆群的承载效率,因此锚杆数量存在上限。基础承载力几乎随锚杆直径的增加呈线性提高,锚杆直径越大对基础稳定越有利,因此在可行的情况下,应尽可能地选用大直径锚杆。锚杆环直径的增大相当于增大了基础抗倾覆力矩的力臂,因此对弯矩承载力是有利的,但由于锚杆群对地基等效刚度的改变,竖向承载力会随着锚杆环直径的增大而先增后减。设计时要综合考虑各个承载力因素,选用合适的锚杆环直径。
A novel type of offshore wind turbine foundation,which is named gravity foundation with anchors,has been proposed recently.The effects of key parameters of anchor on bearing behavior of this type of foundation were investigated in this study by carrying out the finite element analysis.It was found that increasing the number of anchors not only improves the bearing capacity of foundation but also reduces the axial force of each anchor.However,when the number of anchors is increased to certain extent,the spacing between two anchors becomes too small and then causing the superposition of stress and reducing the bearing efficiency of anchors.Therefore,the number of anchors should be optimized.Regarding the effect of diameter of anchors,the analysis showed that the bearing capacity of foundation increases almost linearly with the diameter of anchors.In other words,the larger the diameter of anchors is,the greater contribution for the stability of foundation provided by the anchors.Therefore,the diameter of anchors should be as large as possible.It was also found that the increase in the diameter of anchor rings is equivalent to the increase in the arm of anti-moment provided by the anchors.However,since the anchors can change equivalent stiffness of the subsoil,the bearing capacity under vertical loading increases firstly but decreases subsequently as the diameter of anchor ring increases.Consequently,it is essential to evaluate bearing capacity from various aspects and determine appropriate diameter of anchor rings for design.
出处
《中国工程科学》
北大核心
2014年第8期69-73,共5页
Strategic Study of CAE
基金
国家自然科学青年基金项目(50909030)
深圳市龙岗区软科学研究项目(深龙科[2011]3)
中国水利水电科学研究院科研专项(岩集1238)
关键词
海上风机
重力式基础
锚杆
三维有限元分析
offshore wind turbine
gravity foundation
anchor
three-dimensional finite element analysis
