【作者】 闻建军；

【导师】 张俊发； 刘云贺；

【作者基本信息】 西安理工大学 ， 防灾减灾工程及防护工程， 2005， 硕士

【摘要】 上部结构与地基、基础共同作用是当前的一个热点研究课题,它是随着高层建筑大量兴建及计算机技术迅速发展而产生的。目前,上部结构与地基基础共同作用问题越来越受到工程界的重视。在目前建筑结构设计中,把上部结构看成是柱端固接于基础上的独立结构,这种传统的设计方法不考虑上部结构与地基和基础共同作用的影响,计算结果与实际有较大的出入,尤其是在高层建筑中,不合理的现象更加明显。高层建筑的上部结构、基础同地基是一个统一的有机整体,三者相互联系、相互影响。在建筑结构设计中,共同作用的影响是不容忽视的。 本文以实际工程项目——陕西省邮政电信网管中心大楼为研究对象,基于大型有限元程序ANSYS,将群桩基础视为复合材料,建立了合理、有效的分析模型,进行了共同作用结构静力和动力特性分析研究。本文研究内容及结论如下:(1)建立地基基础模型,施加等效温度荷载模拟了停止降水致使局部桩出现的受拉现象,并对此现象做了定性及定量的解释;(2)简化了单桩有限元模型,并将群桩基础中桩—土体系作等效连续化处理,视为一种复合材料,建立了桩土复合体材料的本构关系和等效复合体模型。结果表明等效复合体模型很好地反映出群桩基础的传力机理,这样大大降低了有限元分析的难度,为利用大型通用有限元分析软件分析超高层建筑的上下部共同作用开辟了有效的途径;(3)通过对考虑上部结构—基础—地基共同作用模型的静力分析,以及同建立在刚性地基上模型的比较,得出了上部结构内力及地基沉降的规律,筏板厚度及地基弹性模量对整体结构的影响;(4)对考虑共同作用后的上部结构进行了动力特性分析,得出上部结构一基础一地基共同作用(与刚性地基上的结构相比)使得结构动力特性发生改变一自振周期延长,振型发生改变。关键词:筒中筒结构,上下部结构共同作用,有限元程序,ANSYS,等效温度荷载,等效复合体模型,动力特性更多还原

【Abstract】 As the number of the tall-building and computer technology were developed rapidly and emerged, interaction between superstructure and foundation becomes a jumped-up research subject. At present, the question of interaction between superstructure and foundation is paid attention to more and more by project circle. In the structural design of the building at present, regard the superstructure as the top of column be root the base of independent structure, which does not consider interaction between superstructure and foundation. It caused a big discrepancy in the result of calculation and reality. The unreasonable phenomenon is more obvious, especially in tall-building. Superstructure in tall-building, base and foundation are an organic whole. The three connecting each other and influencing each other .In the structural design of the building, influence of interaction can not be ignored.This paper looked at the practical project - the building of post and telecommunication and administration of networks in Shanxi as the research example. The paper used large-scale finite element program (ANSYS), looked grouped piles foundation as the composite material, established reasonable and efficient analysis model, and made research on interaction structure static and dynamic behavior. The contents and results of this paper were as follows: (l)The base model was established, some pile tensile phenomenon for which the throwequivalent thermal load simulated stopped dewatering, and the phenomenon was explained in quality and in quantity.(2)The single pile finite element model was simplified, and the pile-soil system in grouped piles foundation was looked as one kind of composite material in terms of the equivalent continuum method ,on this base, the pile-soil composite material’s constitutive relation and equivalent complex model were established. The result showed the equivalent complex model reflected the grouped piles foundation’s load transfer mechanism well, which reduced the finite analysis difficulty and explored efficient solution for the interaction between superstructure and foundation of ultrahigh-rise building’s analysis in order to take advantage of finite element software.(3)The superstructure internal force and the foundation settlement law, the raft thickness and the foundation elastic modulus’ effect were received by analyzing the superstructure-soil interaction model and comparing the model established on the rigid foundation. (4)The superstructure in regard of mutual interaction was analyzed in the way of dynamic behavior ,and the conclusion that the superstructure-soil interaction(compared with the rigid foundation’s structure) changed the structure dynamic behavior-the natural period was prolonged and the modes of vibration was changed was made in this paper.更多还原