海上风机大直径单桩水平-摇摆耦合振动特性  

Analysis on horizontal-rocking vibrations of monopile supporting wind turbine

作　　者：陶文艳 贺瑞[1] 郑金海[2] TAO Wenyan;HE Rui;ZHENG Jinhai(College of Harbor, Coastal and Offshore Engineering, Hohai University, Nanjing 210098;Ministry of Education Key Laboratory of Coastal Disaster and Defense, Hohai University, Nanjing 210098, China)

机构地区：[1]河海大学港口海岸与近海工程学院,江苏南京210098 [2]河海大学海岸灾害及防护教育部重点实验室,江苏南京210098

出　　处：《河海大学学报（自然科学版）》2018年第3期260-267,共8页Journal of Hohai University(Natural Sciences)

基　　金：国家自然科学基金青年基金(51509082);江苏省自然科学基金(BK20150804)

摘　　要：基于弹性半空间理论,在Abaqus有限元软件中建立海上风机三维大直径薄壁空心桩-土动力相互作用模型,通过荷载控制法研究桩的水平-摇摆耦合振动,分析无量纲频率、单桩长径比、厚径比、桩土弹性模量比值、桩基周围冲刷对单桩动力阻抗的影响,并将所得结果无量纲化,增加其适用性。研究结果表明,无量纲频率对桩基动力特性的影响与其他因素紧密相联;长径比、弹性模量比、厚径比、桩基周围冲刷坑深度对桩基动力特性均存在较大影响;刚度随着长径比的增大而增大,但存在一定的临界桩长,在无量纲频率较低时,阻尼的趋势与刚度类似;当基础周围的冲刷深度达到2倍直径时,基础的刚度将会下降到原来的1/3左右,且阻尼的下降也非常显著。A 3D-FEM model involving the dynamic interaction of large diameter monopile and soil was established with the Abaqus software based on the elastic half-spacetheory. Then,the coupled horizontal-rocking vibration of monopilehas been analyzed. The influence of the dimensionless frequency,pile length-radius ratio,pile thicknessradius ratio,pile-soil elastic modulus ratio,scour depths around the pile to the dynamic impedance of the pile are discussed and the results are nondimensionalized to improve its applicability,which show that the influence of dimensionless frequency on the dynamic characteristics is closely related to other factors. Meanwhile,the pile length-radius ratio,pile-soil elastic modulus ratio,pile thickness-radius ratio,and scour depths around pile have a great influence on the dynamic characteristic of monopile.The study also found that the stiffness increases with the increase of length-radius ratio and there is a certain critical pile length. Damping has the same trend in a low dimensionless frequency. When the scour depth around the foundation reaches two times the diameter,the stiffness of the foundation will drop to about 1/3 of original value and the decrease of damping is also very significant.

关 键 词：弹性半空间理论 大直径单桩基础 水平-摇摆耦合振动 动阻抗 冲刷 弯矩 剪力 

分 类 号：TU473[建筑科学—结构工程]