【作者】 黄艳；

【导师】 王自法；

【作者基本信息】 中国地震局工程力学研究所 ， 防灾减灾工程及防护工程， 2012， 博士

【摘要】 本文围绕大跨度斜拉桥结构的地震动输入方式、土-结相互作用以及桥梁动水作用问题展开了如下研究：1.刚性地基地震动输入方式下，采用引入一个‘时差’的方式考虑了行波效应对一座七跨全漂浮结构体系斜拉桥结构的影响，比较了地震行波激励与一致激励作用下桥梁结构关键部位动力响应，分析了两种激励方式下桥梁结构关键部位动力响应的差异，阐明了行波激励作用对桥梁结构动力响应的影响规律，给出了相应抗震措施的建议和方法。2.针对多跨径大跨度斜拉桥等多波源问题，分别基于刘晶波考虑柱面衰减波和杜修力考虑平面波与远场散射波叠加的单点源粘弹性人工边界，利用波场叠加原理推导出一种多源加权集中粘弹性人工边界条件，给出了其弹簧系数、阻尼系数的计算公式，并通过二维偏心单点源、偏心多点源以及多散射源算例讨论了本文多源加权集中粘弹性人工边界的计算精度和稳定性。3.采用直接法建立了结构-地基整体分析模型，利用本文多源加权集中粘弹性人工边界，实现了基于粘弹性人工边界的地震动输入，分析了地基-结构动力相互作用全漂浮结构体系斜拉桥结构动力响应的影响。通过比较基于粘弹性人工边界的地震动输入方式下与采取引入一个‘时差’的基于刚性地基地震动输入方式下桥梁结构各关键部位动力响应的差异，提出了行波激励采取引入一个‘时差’的方式在实现大跨结构桥梁各支撑点地面运动模拟的局限性，论证了本文基于多源加权集中粘弹性人工边界地震动输入方式和建议分析模型对于建造条件复杂超大跨桥梁的地震动力响应分析的合理性。4.采用附加质量法，分别基于刚性地基地震动输入和粘弹性人工边界地震动输入两种地震动输入方式，分析了桥墩动水作用对全漂浮结构体系斜拉桥结构动力响应的影响。比较了两种地震动输入方式下，全漂浮结构体系斜拉桥结构关键部位动力响应的异同点，论证了考虑SSI+动水耦合作用对结构地震反应分析和抗震设计的必要性。更多还原

【Abstract】 The seismic design of large-span cable-stayed bridge has been a topicwith special focus in current research for its complicated constructionconditions. In this paper, the method of seismic ground motion inputing,soil-structure interaction and the hydrodynamic effect of large-spancable-stayed bridge are studied.The results are shown that:1. In the fixed-foundation ground motion input mode, the influence oftravelling wave effect on a seven-span cable-stayed bridge with fully floatingstructure system is considered by way of introducing a ‘time difference’ intothe ground motion time history of each support point of bridge. The dynamicresoponse of key parts of cable-stayed bridge to the seismic travelling waveand seismic uniform excitation are given. By comparing with the dynamicresponse of cable-stayed bridge to seismic uniform excitation, the differenceof that of cable-stayed bridge to seismic travelling wave excitation isdiscussed. The effects of latter are stated, and the effective seismicfortification measures are suggested.2. The seismic analysis of large-span cable-stayed bridge with multispans is a multi-source scattering problem in numerical wave field. Based ontwo typical single-source visco-elastic artificial boundary, that are, LiuJingbo’s boundary which is set up on a basis of cylindrical evanescent waveand Du Xiuli’s boundary which is set up on a basis of plane wave and thesuperposition of far-field scattering wave, a multi-source weigthingconcentrated visco-elastic artificial boundary by using stacking principle ofwave fields. The formulas for calculating its spring coefficient and dampingcoefficient are givien. The accuracy and the stability of this boundaryconditions discussed by giving verification examples such as the2D eccentricsingle-point source problem, the2D eccentric multi-point source problem andthe2D multi-source scattering problem.3. Based on the structure-foundation integral model which is set up byadopting direct method and the multi-source weigthing concentratedvisco-elastic artificial boundary, the visco-elastic artificial boundary groundmotion input mode for bridge is realized. The influence of soil-structureinteraction on the dynamic resoponse of cable-stayed bridge with fullyfloating structure system is analyzed. By comparing the seismic resoponse ofcable-stayed bridge in visco-elastic artificial boundary ground motion inputmode to that in the fixed-foundation ground motion input mode, the differenceof the dynamic resoponse of key parts of cable-stayed bridge in two input modes are discussed. The limitations of the fixed-foundation ground motioninput mode by introducing a ‘time difference’ into the ground motion timehistory of each support point of bridge are analyzed. The ground motion inputmode based on multi-source weigthing concentrated visco-elastic artificialboundary and the structure-foundation integral model are proposed fordynamic ananlysis of large-span cable-stayed bridge under complicatedconditions.4. The hydrodynamic effects on cable-stayed bridge with fully floatingstructure system in two different ground motion input modes are modeled byadded mass. The difference of the seismic resoponse of key parts ofcable-stayed bridge in two input modes are compared, which demonstratesthat it is necessary for seismic analysis and design of large-span cable-stayedbridge to consider the coupling interaction of hydrodynamic effect andsoil-structure interaction.更多还原