八度区超高层框架—核心筒结构布置选型及设计

发布时间：2018-03-25 03:30

本文选题：超高层结构　切入点：框架-核心筒　出处：《清华大学》2015年硕士论文

【摘要】：超高层建筑不但可以更好地解决大城市人口数量不断增长所导致的用地紧张问题,还是一个国家经济发展水平与工程技术水平的综合体现。随着中国经济飞速发展,大型城市中超高层建筑也日益增多。由于中国是一个地震频发的国家,许多大型城市位于8度设防区,随着建筑高度的增加,水平荷载在结构设计过程中逐渐成为了关键因素。如何在结构设计中寻求最佳方案,以控制结构在地震作用下的侧向变形,保证结构安全,已成为了亟需解决的重要课题之一。而项目初步设计阶段的结构选型以及布置优化直接影响结构整体性能以及经济性,具有极其重要的地位。本文以350m高的西安利科国际金融中心超高层项目为工程实例,首先建立了8个模型,分别比较了结构体系,框架柱间距,核心筒尺寸以及外框梁截面对于结构抗震性能以及经济性的影响。根据计算结果得出了以下结论:1、选用框架-核心筒结构体系在材料用量上会略多于采用巨型结构体系;2、框架-核心筒结构外框柱距越大,为了满足抗侧刚度的要求,外框架所需要的材料越多;3、增大结构核心筒尺寸有利于整体抗侧性能。根据初步设计选型结果,本项目最终主体结构型式为核心筒尺寸30mX30m,外柱距6m的框架-核心筒结构。随后在不改变核心筒及外框架构件尺寸的情况下,通过改变加强层的布置方案,建立了5个模型进行对比分析。研究表明在第二、第四避难层设置加强层,并且在第五避难层设置环向桁架能够有效控制结构侧向位移,为工程设计提供了一定参考依据。本文基于最终结构方案模型,使用PKPM结构设计软件按照规范要求进行了结构弹性分析,证明经过合理优化设计的结构方案各指标均满足规范限值,构件承载力满足设计要求。针对结构超限情况,本文通过弹塑性时程分析验证了结构在罕遇地震作用下的安全性,证明结构满足“小震不坏,中震可修,大震不倒”的抗震设计原则。针对结构关键节点以及薄弱部分,本文使用abaqus有限元软件进行建模分析,获得了节点在罕遇地震作用下的内力分布,对部分薄弱位置给出了设计建议。本文着重强调了前期结构选型优化的重要性,并对项目初步设计优化过程进行了的总结提炼,希望能为类似的超高层结构方案设计提供一定的参考,简化结构设计人员工作内容。
[Abstract]:Super high-rise buildings can not only better solve the problem of land shortage caused by the increasing population in large cities, but also reflect the level of economic development and engineering technology of a country. With the rapid development of China's economy, The number of super-tall buildings in large cities is also increasing. As China is a earthquake-prone country, many large cities are located in 8-degree fortified areas, and as the building height increases, The horizontal load has gradually become a key factor in the structural design. How to find the best scheme in the structural design to control the lateral deformation of the structure under earthquake to ensure the safety of the structure. It has become one of the important problems that need to be solved, and the structure selection and layout optimization in the initial design stage of the project directly affect the overall performance and economy of the structure. In this paper, taking the 350m tall project of Xi'an Lico International Financial Center as an example, eight models are established, and the structure system, frame and column spacing are compared respectively. The effects of the size of core tube and the section of external frame beam on the seismic performance and economy of the structure are discussed. According to the calculation results, the following conclusion is drawn: 1: 1, the material consumption of the frame-core tube structure system is slightly larger than that of the giant junction system. The larger the distance between the outer frame and the column of the frame-core tube structure is, In order to meet the requirements of lateral stiffness, the more materials are needed for the outer frame, the larger the size of the core tube is in favor of the overall anti-lateral performance. The final main structure of the project is a frame-core tube structure with a core cylinder size of 30mX 30m and a outer column spacing of 6m. Then, without changing the size of the core tube and the outer frame members, the arrangement of the strengthened layer is changed. Five models are established for comparative analysis. The results show that the reinforcement layer is set up in the second and fourth sheltered layer, and the annular truss in the fifth refuge layer can effectively control the lateral displacement of the structure. In this paper, based on the final structural scheme model, PKPM structural design software is used to analyze the structural elasticity according to the specifications. It is proved that every index of the structural scheme after reasonable optimization design meets the specified limit value and the bearing capacity of the member meets the design requirements. In view of the structure exceeding the limit, this paper verifies the safety of the structure under the action of rare earthquake by elastic-plastic time-history analysis. It is proved that the structure meets the aseismic design principle of "small earthquake is not bad, medium earthquake is repairable, large earthquake is not collapsed". For the key nodes and weak parts of the structure, the abaqus finite element software is used to model and analyze the structure. The internal force distribution of the joints under the action of rare earthquakes is obtained, and the design suggestions for some weak positions are given. This paper emphasizes the importance of the pre-stage structural selection and optimization, and summarizes and refines the optimization process of the preliminary design of the project. It is hoped that this paper can provide some reference for the design of similar super-high-rise structures and simplify the work of structural designers.
【学位授予单位】：清华大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU973.17

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