【作者】 武成浩；

【导师】 姚谦峰；

【作者基本信息】 北京交通大学 ， 结构工程， 2010， 博士

【摘要】 考虑土—结共同作用效应对于正确预测高层建筑结构地震反应以及高层建筑结构抗震性能评估有非常重要的意义,是当前结构工程研究领域里的热点和难点。近年来一些学者在这方面做了大量工作并取得不少成果,但由于问题本身的复杂性,尚有许多问题亟待解决。本文在现有研究的基础上,采用理论分析与数值模拟相结合的方法,研究高层建筑结构—桩(筏)基础—地基共同作用体系的耦合作用机理,提出了具有四个广义位移的平板弯曲理论以及高层建筑结构—桩(筏)基础—地基共同作用体系整体建模与分析方法,利用大型有限元软件ABAQUS建立了考虑土—结共同作用效应的高层建筑结构三维实体有限元精细化整体模型,分析了土—结共同作用效应对高层建筑结构的地震响应影响,并对影响结构地震反应的主要因素进行了详细参数对比分析,揭示了体系动力共同作用的内在规律,提出了高层建筑结构抗震设计建议,并在此基础上提出了基于能力谱方法考虑土—结共同作用效应的改进高层建筑结构抗震性能评估方法。论文的主要研究内容及所取得的研究成果具体包括以下几个方面：(1)研究了高层建筑结构—桩(筏)基础—地基的共同作用机理和分析方法,指出了现有机理分析和分析方法的不足之处,提出了具有四个广义位移的平板弯曲理论,考虑了横向伸缩广义位移Φ3,用变分法推导了弹性地基上四边自由矩形中厚板的控制微分方程,丰富了筏板计算理论,将土、(筏)桩基础、高层建筑结构作为一个整体,采用桩侧土体和桩端土体分别建模的方法,提出了高层建筑结构—桩(筏)基础—地基共同作用体系的整体建模与分析方法,为共同作用体系有限元地震响应分析提供了理论基础。根据高层建筑结构—桩(筏)基础—地基共同作用体系整体建模方法,利用大型有限元软件ABAQUS建立了经历汶川地震的某高层建筑结构共同作用体系三维实体线弹性有限元精细化模型,研究了该体系的自振特性并结合土体参数的变化进行了影响性分析,揭示了桩端土体和桩侧土体对上部结构自振周期影响的不同规律,比较了考虑与不考虑共同作用效应情况下结构的地震反应规律,对比分析了桩侧土体和桩端土体分别建模方法与常规建模方法对结构地震响应的不同影响规律。(2)采用高层建筑结构地震反应整体建模与分析方法,考虑了混凝土和土体的材料非线性、桩(筏)基础与土体的接触非线性,利用ABAQUS建立了高层建筑结构—桩(筏)基础—地基的三维实体非线性有限元精细化整体模型,根据场地土特性合理选取了强震记录作为地震动输入,比较了考虑与不考虑共同作用效应情况下结构的地震反应规律,分析了不同工况罕遇地震作用下共同作用体系的非线性地震反应,并对影响结构地震反应的关键因素(上部结构非线性、土体材料非线性、土体参数变化、边界条件变化,接触非线性等)进行了详细对比分析,结合汶川地震震后调查揭示了高层建筑结构共同作用体系动力反应的规律,提出了高层建筑结构设计建议。(3)研究了FEMA440考虑土—结共同作用效应的能力谱方法,并对其计算土弹簧刚度的方法进行了改进,提出了改进的基于共同作用理论的抗震性能评估方法,使其能够与我国的建筑抗震设计规范相容,适用于我国高层建筑结构的抗震性能评估,并为我国抗震规范的修订提供了参考。在此基础上,选取了某工程实例,利用改进后的考虑土—结共同作用效应的抗震性能评估方法对其进行了非线性静力分析,将其计算结果与非线性动力时程反应分析的计算结果进行了比较,验证了改进的基于共同作用理论的抗震性能评估方法在实际工程应用中的可行性。更多还原

【Abstract】 It’s of great significance for predicting seismic response and seismic performance assessment of high-rise building considering soil-structure interaction effect,which is an emphasis and difficulty in the field of seismic engineering.Some scholars have done a lot of job and got great achievement in the field,but there’s still a lot to do due to its complexity.Based on present research works,theorical analysis method and numerical simulation way were combined to study coupling effect mechanism of high-rise building-pile-foundation system.Bending theory of flat plate with extensive four-displacement and overall modelling and analysis method for high-rise building-pile-foundation system were put forward. High-rise building interaction system three-dimensional solid finite element fine modeling was set up by software ABAQUS.The influence of soil-structure interaction effect for seismic response of high-rise building was analysized and parameter analysis was performed accordingly. Dynamic interaction mechanism was disclosed and advice and suggestions were given for designing pratice. Seismic performance assessment method for high-rise buildings based on capacity-spectrum method including soil-strucure interaction effects was put forward. The main research and results involved in the dissertation includes the following parts:(1) Summarize status in quo of seismic analysis method and seismic performance assessment for high-rise building and points out questions to be solved based on quantities of literature domestic and abroad.Discuss and summarize interaction mechanism and analysis method for high-rise building-pile-foundation system and indicated problems to be improved on.Bending theory of flat plate with extensive four-displacement was put forward considering transverse extension and contraction displacementΦ3 and governing differential equations are accurately derived for moderately thick rectangular plates on elastic foundation by means of variational method.An overall analysis method was put forward for high-rise building-pile-foundation system in which soil and structure were roled into one which pave the way for high-rise building-pile-foundation system seismic response analysis.High-rise building-pile-foundation three-dimensional solid finite element fine modeling was set up for the real Jiannanchun Hotel high-rise building which endured the Wenchuan earthquake by software ABAQUS.The principle of the influence of pile bottom soil and pile side soil upon superstructure vibration characters was drawn after studying the interaction system vibration characteristic.The different principle of seismic response under or without interaction effect,according to method suggested in the paper or conventional were compared.(2) The new overall analysis method put forwarded in chapter 2 was used for high-rise building-pile-foundation three-dimensional solid finite element fine modeling.Concrete and soil nonlinearity and contact nonlinearity were considered in the model and great earthquake records were selected.Nonlinear time-history analysis were performed for the model and parameter influencial analysis were done afterwards for superstructure,soil material,soil parameter change,boundary conditions and contact nonlinearity. Some suggestions were given for high-rise building design after anslysis and investigation on site.(3) The capacity-spectrum method including soil-strucure interaction effects according to FEMA440 was introduced in the paper and the way for calculating the stiffness of soil was improved on to match Chinese engineering practice according to Code for seismic design of buildings. A real project was selected to be analysized according to improved capacity-spectrum method including soil-strucure interaction effects.The method was improved feasible after comparison with nonlinear dynamic time-histoty analysis.更多还原