砂土场地桩-筒复合基础地震响应离心振动台试验  

Seismic response of the monopile-bucket hybrid foundation in offshore sand deposit through centrifuge modeling

作　　者：杨威 张泽旺 梁发云[2] 王奕康 田会元 YANG Wei;ZHANG Zewang;LIANG Fayun;WANG Yikang;TIAN Huiyuan(China Three Gorges Corporation,Wuhan 430010,China;Key Laboratory of Geotechnical and Underground Engineering of China Ministry of Education,Tongji University,Shanghai 200092,China;Shanghai Investigation,Design&Research Institute Co.,Ltd.,Shanghai 200434,China)

机构地区：[1]中国长江三峡集团有限公司,武汉430010 [2]岩土及地下工程教育部重点实验室(同济大学),上海200092 [3]上海勘测设计研究院有限公司,上海200434

出　　处：《哈尔滨工业大学学报》2024年第2期95-104,共10页Journal of Harbin Institute of Technology

基　　金：国家自然科学基金(52178346);上海勘测设计研究院有限公司科研项目(2021FD(8)-021)。

摘　　要：地震作用容易引起砂土地基中的海上风机基础液化失效,单桩-筒型复合基础(简称桩-筒复合基础)结合了单桩基础和吸力筒基础的优势,是一种新颖的海上风机基础形式。针对砂土场地桩-筒复合基础地震响应,开展干砂及饱和砂的单桩和桩-筒复合基础的离心振动台试验,采用白噪声和具有不同频谱成分的地震波进行激振,得到两种基础形式在砂土场地中的自振频率、超孔压累积、风机加速度响应以及基础弯矩分布等。结果表明:饱和场地中筒基下的浅层土体,其超孔压累积会有所衰减,加速度幅值则被相应放大;饱和场地中单桩浅部弯矩响应较大,风机产生明显的残余位移,相比单桩,桩-筒复合基础加速度响应更大,但其在限制水平位移方面具有明显优势。研究结论对于桩-筒复合基础的抗震分析具有参考价值。Seismic action tends to result in the liquefication failure of offshore fan foundation in the sand deposit.Monopile-bucket hybrid foundation is a novel type of offshore fan foundation,combining the advantages of monopile and suction bucket foundations.To investigate the seismic response of this hybrid foundation in sand,a series of centrifugal shaking table model tests of monopile and the hybrid foundations in dry and saturated sand were conducted.White noise and seismic waves with different frequency spectrum components were used to stimulate the vibration for obtaining the natural vibration frequency,excess pore pressure accumulation of foundation soil,acceleration response of the offshore wind system and foundation bending moment distribution of the two foundation forms in sandy soil.The results show that the excess pore pressure of soil in saturated soil decreases in shallow depth under the bucket component of the hybrid foundation,while the acceleration amplitude is enlarged correspondingly.The shallow bending moment response of the monopile in saturated site is relatively larger with the turbine exhibiting obvious residual displacement.Compared with the monopile,the hybrid foundation shows greater acceleration response and smaller horizontal displacement in tests.The study provides a fresh reference for the seismic design of offshore wind structures with monopile and monopile-bucket hybrid foundations.

关 键 词：砂土场地 桩-筒复合基础 离心振动台 地震响应 

分 类 号：U441.3[建筑科学—桥梁与隧道工程]