摘要
海上风力发电机的基础承受着结构自重及风、波浪、水流等多种循环荷载,而风力发电机组运行对基础的承载力和变形有严格要求.针对近海风机开口管桩单桩基础,通过PFC2D数值模拟研究了水平单向循环荷载对单桩基础受力变形的影响.结果表明:水平单向循环荷载作用下,桩顶累积位移随着循环荷载谷值与峰值的比值ζc的增大前期增加速率较快,而后期较慢,但并未改变桩体转动中心的位置,约为0.85倍的桩体埋深;ζc值越大,桩基初期卸载刚度越大,但稳定后卸载刚度的终值相近,约为6.70 kN/mm;随ζc值的增大,桩顶主动区局部土体扰动程度增大,但影响范围大致相同,严重扰动区为2~3倍桩径;桩侧摩阻力降低幅度随ζc值增加而增大,且前期侧摩阻力降低速率增加,后期侧摩阻力均趋于稳定状态.
The foundation of the offshore wind turbine bears structural self-weight and many cyclic loads such as wind,wave and water flow,while the operation of wind turbines has strict requirements on the bearing capacity and deformation of the foundation.Aiming at the single pile foundation of offshore wind turbine open pipe pile,PFC2D numerical simulation was carried out to study the influence of horizontal unidirectional cyclic load on the deformation of single pile foundation.The results show that,under the horizontal unidirectional cyclic load,the cumulative displacement of pile top increases rapidly in the early stage with the increase ofζc,the valley-to-peak ratio of cyclic load,but decreases in the later stage.However,the position of the rotating center of pile body is not changed,which is about 0.85 times of the buried depth of pile body.The larger the value ofζc is,the greater the unloading stiffness of pile foundation at the initial stage will be,but the final value of unloading stiffness after stabilization is similar,which is about 6.70 kN/mm.With the increase ofζc value,the disturbance degree of local soil mass in the active area of pile top increases,but the influence range is roughly the same.The serious disturbance area is 2~3 times the diameter of pile.The reduction amplitude of pile lateral friction increases with the increase ofζc value,and the reduction rate of lateral friction increases in the early stage,and the lateral friction tends to be stable in the later stage.
作者
刘俊伟
黄孝义
韩金朋
赵彦平
李欣
LIU Jun-wei;HUANG Xiao-yi;HAN Jin-peng;ZHAO Yan-ping;LI Xin(School of Civil Engineering,Qingdao University of Technology,Qingdao 266033,China;Cooperative Innovation Center of Engineering Construction and Safety in Shandong Blue Economic Zone,Qingdao University of Technology,Qingdao 266033,China)
出处
《青岛理工大学学报》
CAS
2019年第6期8-15,共8页
Journal of Qingdao University of Technology
基金
国家自然科学基金资助项目(41502304
41772318)
中国博士后科学基金资助项目(2015M581940)
住房和城乡建设部科学技术计划项目(2014-K3-026)
山东省重点研发计划项目(2018CiSF121002
2017GSF20107)
泰山学者工程专项经费资助项目(鲁政办字〔2015〕212号)
青岛市应用基础研究项目(16-5-1-34-jch)
大连理工大学海岸和近海工程国家重点实验室开放基金项目(LP1712)
关键词
开口管桩
单向循环荷载
颗粒流数值模拟
累积位移
桩侧摩阻力
open pipe piles
unidirectional cyclic load
numerical simulation of particle flow
cumulative displacement
pile side friction
