摘要
采用有限元分析软件ABAQUS建立了非均质土中海上风电单桩基础数值计算模型,将桩基础受到的波浪、洋流及风荷载等效成双向对称循环荷载,对水平循环荷载作用下桩身水平位移、桩身剪力、桩身弯矩和桩侧土抗力进行了研究,并对不同循环次数下桩身水平位移进行了对比分析.研究表明,桩身水平位移随时间变化逐渐累积,随着循环次数的增加,泥面处桩身最大位移发生的时间点滞后;桩身剪力出现负值;桩身弯矩最大值发生在浅层土体;桩身外壁土抗力曲线随时间的变化在埋深约2/3处出现分界点,分界点上下范围内土抗力变化规律正好相反,在淤泥土和粉砂土分界面处增加显著;不同时间点桩身内壁沿埋深承担的荷载基本不变.
Wind energy is a new kind of inexhaustible energy.It is gradually replacing the traditional energy as its pollution-free and renewable.China has a long coastline,abundant offshore resources,and vast offshore space.Offshore wind farms have gradually become the focus of wind-power development.Large-diameter single-pile foundations are being widely used in the field of offshore power generation because of advantages including convenient manufacture and installation,clearer stress conditions compared with pile groups,and affordable cost and economy.Therefore,it becomes significantly relevant to study the dynamic response characteristics of large-diameter single-pile foundations under horizontal cyclic loads to eliminate the dangers hidden in engineering and installation and ensure normal usage during service.A numerical calculation model of an offshore,wind-power monopile foundation in heterogeneous soil was established by the finite element analysis software ABAQUS.The wave,ocean current,and wind load on the monopile foundation were equivalent to a bidirectional symmetrical cyclic load.The horizontal displacement,shear force,and bending moment along the pile shaft,and pile-side soil resistance under the horizontal cyclic load were studied.Furthermore,the horizontal displacements along the pile shaft under different cyclic times were compared with one another and analyzed.The results show that the horizontal displacement along the pile shaft accumulates gradually with time,and with increase in the number of cycles,the time lag of the maximum displacement of the pile body at mud surface occurs.The shear force along the pile shaft appears negative.The maximum bending moment of the pile body occurs in shallow soil.The variation in the soil-resistance curve of the pile body vs time occurs at a cutoff point at approximately 2/3 of the buried depth.Additionally,the variation laws of soil resistance within the upper and lower boundaries of the cut-off point are just the opposite of each other.The soil resistance increases significantly at the interface between silt and silty soil.The load along the buried depth of the inner wall of the pile remains unchanged at different time points.
作者
孔德森
刘一
邓美旭
李亚洲
KONG De-sen;LIU Yi;DENG Mei-xu;LI Ya-zhou(Shandong Key Laboratory of Civil Engineering Disaster Prevention and Mitigation,Shandong University of Science and Technology,Qingdao 266590,China;College of Civil Engineering and Architecture,Shandong University of Science and Technology,Qingdao 266590,China;China Railway Construction Group Shandong Co.Ltd.,Qingdao 266100,China)
出处
《工程科学学报》
EI
CSCD
北大核心
2021年第5期710-719,共10页
Chinese Journal of Engineering
基金
山东省自然科学基金资助项目(ZR2019MEE027)
国家自然科学基金资助项目(41372288)。
关键词
非均质土
海上风电
单桩基础
动力响应
水平循环荷载
heterogeneous soil
offshore wind power
monopile foundation
dynamic response
horizontal cyclic load
