王雪菲 ,马成良 ,李家乐
AuthorsHTML:王雪菲 ^{1, 2}，马成良 ^{1, 2}，李家乐 ^{1, 2}
AuthorsListE:Wang Xuefei,Ma Chengliang,Li Jiale
AuthorsHTMLE:Wang Xuefei^{1, 2}，Ma Chengliang^{1, 2}，Li Jiale^{1, 2}
Unit:1. 河北工业大学土木与交通学院，天津 300401；
2. 天津市装配式建筑与智能建造重点实验室，天津 300401

Unit_EngLish:1. School of Civil and Transportation Engineering，Hebei University of Technology，Tianjin 300401，China；
2. Tianjin Key Laboratory of Prefabricated Building and Intelligent Construction，Tianjin 300401，China

Abstract_Chinese:筒型基础作为海上风机的一种新型基础结构，具有安装方便、重复使用、成本低等显著优点．在地震荷载 作用下，地基土可能发生液化，液化后砂土的强度和刚度会降低，导致地基承载能力下降，筒型基础可能发生过大 竖向沉降，严重威胁风机的运行．针对筒形基础影响范围内土体的地震响应规律，本研究开展了一系列离心机试 验，记录了筒体周围砂土地基加速度、孔隙水压及沉降的时程曲线．基于 OpenSees 开源平台进行了一系列数值模 拟工作，揭示了土体的应力、应变、孔压等动态响应，通过对试验超静孔压比结果的校正验证了数值计算模型的可 靠性，进而分析了基础与土体相互作用下地基的液化规律及筒型基础尺寸效应对抗液化性能的影响．研究表明，上 部荷载增加了地基中的附加应力，使筒下和筒周围的土体具有较好的抵抗液化能力；由于筒型基础内部土体的排水 路径较长，筒内土体的孔隙水压力消散较慢，数值与同一深度筒外土体的孔隙水压相比偏大；筒型基础的抗液化能 力随着高径比的增大而呈削弱趋势；在深度方向上现筒下的超静孔压比在筒型基础底部附近达到极小值，研究成果 旨在为不同地震设防等级的地区提供设计依据．
Abstract_English:Bucket foundation is a new type of foundation for offshore wind turbines，and it has the advantages of easy installation，reusability，and low cost. Soil may liquefy under seismic loads，causing a reduction in the soil strength and stiffness，and consequently，a decline in the foundation bearing capacity. A bucket foundation tends to undergo excessive vertical settlement and differential settlement，which severely threatens wind turbine safety. In this study，a series of centrifuge tests were conducted to investigate the seismic response of bucket foundation by recording the time histories of acceleration, pore water pressure, and settlement of surrounding sandy soil. Moreover， numerical analysis was conducted using OpenSees to analyze the dynamic properties of soil，such as stress，strain， and pore pressure. The reliability of the numerical model was verified by the centrifuge test results. The liquefaction characteristics of the bucket foundation were illustrated by considering the soil-foundation interaction，and the influ\u0002ence of aspect ratio was demonstrated. The results showed that the soil under and around the bucket had better resistance to liquefaction owing to the additional stress provided by the foundation. Owing to the long drainage path of the soil inside the bucket foundation，the pore-water pressure dissipates more slowly compared with the soil outside the bucket at the same depth. Moreover，the liquefaction resistance decreased with an increase in the aspectratio of the bucket. The excess pore-pressure ratio under the bucket reached a minimal value near the bottom of the bucket foundation along the embedment depth. The study results can serve as a design basis for bucket foundation in seismic areas.
Keyword_Chinese:筒形基础；离心机试验；超静孔压比；附加应力；地震
Keywords_English:bucket foundation；centrifuge test；excess pore-pressure ratio；additional stress；earthquake

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