\r刘 润，马鹏程，练继建

AuthorsHTML:\r刘 润，马鹏程，练继建

AuthorsListE:\rLiu Run，Ma Pengcheng，Lian Jijian

AuthorsHTMLE:\rLiu Run，Ma Pengcheng，Lian Jijian

Unit:\r天津大学水利工程仿真与安全国家重点实验室，天津 300072

Unit_EngLish:\rState Key Laboratory of Hydraulic Engineering Simulation and Safety，Tianjin University，Tianjin 300072，China

Abstract_Chinese:\r我国近海地基以软黏土地基为主，在地震频发的场地中，地震荷载的作用会导致浅层黏土地基的土强度发生弱化，而宽浅式筒型基础是一种新型的海上风电基础，其入土深度较浅，因此宽浅式筒型基础对地震作用下浅层土体的强度弱化较为敏感．为研究黏土中宽浅式筒型基础与地基的地震响应规律，以实际场地中原型宽浅式筒型基础为依据，参照原型宽浅式筒型基础的1 阶自振频率设计并开展了一系列离心机振动台试验，监测了宽浅式筒型基础作用下黏土地基在震中和震后的孔隙水压力响应，分析了宽浅式筒型基础和黏土地基的加速度变化，研究了筒型基础作用下黏土地基的剪应力-剪应变关系，揭示了黏土地基中宽浅式筒型基础结构与地基的动力响应规律．结果表明，地震作用下黏土地基中的超静孔隙水压力累积存在滞后效应，且位于筒型基础中心线上土体的超静孔隙水压力相对较小，宽浅式筒型基础产生的大面积附加荷载作用有利于减小黏土地基振动弱化程度；随着埋深的减小，黏土地基的加速度在EL Centro 波作用下呈线性衰减规律，在SIN 波作用下呈非线性衰减规律，塔筒处加速度与基础顶盖处加速度相当且峰值加速度明显小于浅层地基；基础底面以下土体的应力应变滞回圈随埋深的增加而增大，而基础底面处土体的剪应变明显提高．

Abstract_English:\rSoft clay is the main component of offshore ground in China．In areas prone to frequent earthquakes，the action of seismic loading will lead to the weakening of the soil strength of the shallow bucket foundation of soft clay．The shallow bucket foundation is a new type of foundation for offshore wind turbines．This type of foundation has a shallow buried depth．Thus，the weakening of the soil strength of the shallow bucket foundation of soft clay due to seismic loading has a considerable influence on the stability of the bucket foundation．To investigate the seismic response of the shallow bucket foundation of soft clay，a series of dynamic centrifuge tests，which were designed on the basis of the first-order natural frequency of the shallow bucket foundation，were performed．In the tests，the pore water pressure response of soil during the entire loading period，the acceleration of the shallow bucket foundation of clay ground，and the shear strain and shear stress were measured to determine the seismic response regularity．The results show that seismic loading has a hysteresis effect on the accumulation of pore water pressure．The accumulation of pore water pressure along the centerline of the bucket is smaller than that around the bucket．The additional load on a large area with shallow bucket foundation reduces the degree of weakening of the soil strength of clay due to seismic loading．Under the action of the EL Centro wave，the acceleration of the shallow bucket foundation of clay ground decreases linearly with the decrease in buried depth．Under the action of the SIN wave，the acceleration of the shallow bucket foundation of clay ground decreases nonlinearly with the decrease in buried depth．The acceleration response of the bucket lid is equal to that of the tower drum．Meanwhile，the maximum acceleration of the bucket lid and tower drum is smaller than that of the clay ground．The shear stress-strain response of the clay ground under the bucket increases with the increase in buried depth．The shear strain at the plate of the bucket base also increases．

Keyword_Chinese:宽浅式筒型基础；离心机振动台试验；黏土地基；加速度；孔隙水压力

Keywords_English:shallow bucket foundation；dynamic centrifuge test；clay ground；acceleration；pore water pressure


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