饱和黏土中吸力桶基础离心振动台试验及地震响应分析  

Centrifugal shaking table tests and seismic response analysis of suction caisson foundation in saturated clay

作　　者：崔鹤 黄茂松[1,2] 时振昊 CUI He;HUANG Maosong;SHI Zhenhao(Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China;Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education,Tongji University,Shanghai 200092,China)

机构地区：[1]同济大学地下建筑与工程系,上海200092 [2]同济大学岩土与地下工程教育部重点实验室,上海200092

出　　处：《岩石力学与工程学报》2025年第3期769-780,共12页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(42377153,41902278)。

摘　　要：我国近海风电场表层海床主要为软黏土,易发生循环弱化与变形累积。在地震作用下吸力桶基础及上部结构可发生位移过量累积,威胁风机正常服役。开展单桶及多桶导管架基础风机离心振动台试验,并基于考虑土体小应变刚度的循环加载不排水黏土总应力本构模型,建立吸力桶基础风机地震响应数值模型。通过数值计算与离心模型试验结果进行对比,验证数值方法的合理性。利用建立的数值方法,探究静力加载特性一致条件下,不同吸力桶基础型式(单桶与多桶导管架)对地震荷载下风机上部结构加速度与变形响应的影响,并讨论风机响应与基础型式对地震荷载主频过滤效应的关联关系。研究结果表明:该数值模型可以合理反映黏土地基吸力桶基础及风机结构的地震响应;风机塔顶最终累积位移与其振动幅值具有较强相关性;静力加载特性一致时,与单桶基础相比,多桶基础可过滤部分地震荷载高阶主频振动,从而导致更小的塔顶加速度及累积位移。The shallow seabed in China's offshore wind farms is primarily composed of soft clay that can exhibit remarkable cyclic softening and deformation accumulation.Accordingly,suction caisson foundations and the supported superstructure can show excessive displacement accumulation under seismic loading,and thus threatening serviceability of wind turbine.This works conducts centrifuge shaking table tests for turbine supported by single caisson and multi-caisson jacket foundations in undrained clays,and constructs corresponding numerical model based on an undrained total stress-based constitutive model for cyclic loaded clay accounting for small-strain stiffness.The numerical model was validated against experimental data.By using numerical simulations,this work studies the effects of foundation types on the acceleration and deformation response of wind turbine superstructure under seismic loading.The relationships between turbine seismic response and filtering frequency-contents of earthquake loading via foundations are explored.This study shows that the proposed numerical model can reasonably capture the seismic response of suction caisson foundation and superstructure.There are strong correlations between magnitude of turbine tower accumulative displacement and its vibration intensity during earthquake.When featuring similar static loading characteristics,compared to single-caisson foundation,multi-caisson jacket can filter certain higher-order frequencies of seismic loading,and thus leading to smaller superstructure acceleration and consequently lower cumulative displacements.

关 键 词：土力学 离心振动台试验 吸力桶基础 风机 地震 数值模拟 

分 类 号：TU43[建筑科学—岩土工程]