上海中心大厦巨型框架-核心筒结构竖向地震作用反应分析  

Vertical earthquake action analysis for mega frame-core tube structure of the Shanghai Tower

作　　者：何志军[1] 丁洁民[1] 陆天天[1] 

机构地区：[1]同济大学建筑设计研究院(集团)有限公司,上海200092

出　　处：《建筑结构学报》2014年第1期27-33,共7页Journal of Building Structures

基　　金：上海市科技攻关计划项目(09dz1207704)

摘　　要：上海中心大厦主体结构高度632 m,为带伸臂桁架的巨型框架-核心筒结构,其竖向地震作用反应大且较为复杂。巨型框架与核心筒沿高度的质量和竖向刚度分布特性差异较大,两者的相对振动将导致伸臂桁架产生较大的内力;环带桁架具有转换承重和巨柱弹性支承的特性,相对支承巨柱存在更大的竖向振动放大效应。在分析结构重力荷载的竖向分布特性以及结构自振特性的基础上,通过反应谱和时程分析,对上海中心大厦结构在竖向地震作用下巨柱和核心筒的轴重比、伸臂桁架和环带桁架的内力反应以及巨柱、核心筒和环带桁架的竖向加速度反应及分布特点进行分析。结果表明:上海中心大厦结构的竖向地震作用反应随结构高度增加而增加;处于高区的巨柱和核心筒的轴重比约为低区的2.2倍和2.3倍,高区伸臂桁架和环带桁架在竖向地震作用下的轴力占重力荷载作用下轴力的比例约为低区的2.2倍和4.3倍;高区环带桁架跨中竖向加速度反应较相应标高巨柱增大20%。Shanghai Tower is a super tall building of 632-meter high. For structural efficiency, a special ＇ mega frame- core system with outrigger＇ was developed, which has a characteristic that the vertical earthquake response is large and complicated. The distribution characteristics of the mass and vertical stiffness along the height are different between the mega frame and core tube, so the relative vibration between them will generate large internal force effect in the outrigger trusses; due to the characteristics of gravity load transfer and elastic support of super columns, the vertical seismic response of belt trusses is amplified relative to the super columns. Based on the analysis of the gravity load＇ s vertical distribution and the structural natural vibration characteristics, the vertical earthquake response was systematically studied by response spectrum analysis and time history analysis, including the ratio of axial force to gravity force of the super columns and core tube, the vertical earthquake internal forces of outrigger trusses and belt trusses and the response and distribution characteristics of the vertical acceleration of the core tube and belt trusses. Study results show that, the vertical earthquake effect of the Shanghai Tower increases with the structural height increasing. The ratios of axial force to gravity force of super column and core tube are about 2.2 times and 2.3 times of those in lower zone. The seismic axial forces of outrigger truss and belt truss are about 2.2 times and 4. 3 times of those in lower zone. Compared with the super column at the same elevation, the vertical acceleration of beh truss increases by 20%.

关 键 词：巨型框架结构 伸臂桁架 环带桁架 有限元分析 竖向地震作用反应 轴重比 竖向加速度 

分 类 号：TU973.14[建筑科学—结构工程] TU973.31