超高层建筑结构环带桁架的研究与设计  

Research and Design of the Belt Truss of Super High-Rise Building Structures

作　　者：包联进[1,2] 童骏[2] 严从志 李国强[1] BAO Lianjin;TONG Jun;YAN Congzhi;LI Guoqiang(College of Civil Engineering,Tongji University,Shanghai 200092,China;East China Architectural Design Research Institute Co.,Ltd.,Shanghai 200002,China)

机构地区：[1]同济大学土木工程学院,上海200092 [2]华东建筑设计研究院有限公司,上海200002

出　　处：《建筑钢结构进展》2022年第1期119-127,共9页Progress in Steel Building Structures

摘　　要：框架-核心筒结构是超高层建筑中最常用的结构体系之一。当结构抗侧刚度不足时,在设备层设置水平伸臂桁架可以显著增大结构的抗侧刚度,减小结构位移,降低水平荷载作用下核心筒的倾覆力矩。但是传统的伸臂桁架设置会带来一系列问题,例如容易引起结构刚度、结构内力的突变,产生较大的附加内力,连接节点复杂,施工周期长等。而环带桁架加强层可以很好地避免这些问题。在水平荷载作用下,环带桁架加强层核心筒的转动受到加强层楼板的约束,使环带桁架上、下弦所在楼板产生方向相反的移动趋势。由于变形协调,环带桁架弦杆会随着楼板变形,而外围框架柱约束了环带桁架的移动,在外框柱中产生了一对方向相反的竖向力偶,可以有效减小核心筒的倾覆力矩,减小结构的变形,起到"虚拟伸臂"的作用。针对环带桁架的"虚拟伸臂"的作用机理进行了深入研究与分析,利用数值计算模型对环带桁架的位置、高度及环带桁架层楼板的厚度进行了参数化分析,并结合实际工程案例,对考虑"虚拟伸臂"效应的环带桁架的设计提出了合理化的建议,为"虚拟伸臂"在更多工程中的应用提供了理论指导及设计依据。Frame-core tube structure is a common structural systems in super high-rise buildings.When the structural rigidity is insufficient,setting up a horizontal outrigger on the equipment story can significantly increase structural rigidity,reduce structural displacement,and reduce the overturning moment of the core tube under horizontal load.However,the installation of traditional outrigger truss will cause a series of problems,such as leading to sudden variations in structural rigidity,structural internal force,large additional internal force,complex connection details,and long construction period,et al.However,"virtual outrigger"can avoid these problems well.Under the action of horizontal load,the rotation of the belt truss story core tube is restricted by the floor diaphragms at the top and bottom of the belt trusses,which makes the floor where the upper and lower chords of the belt truss move in the opposite direction.Due to the coordination of deformation,the chord of the belt truss deforms with the floor,and the outer frame column restrains the movement of the belt truss,and a pair of opposite vertical couples are generated in the outer frame column.This reduces the overturning moment and rotation of the core tube,and also effectively reduces the overturning moment of the core tube and reduces the deformation of the structure.This phenomenon is called the"virtual outrigger"effect of belt truss.In this paper,the mechanism of the"virtual outrigger"of belt truss has been analyzed and researched in detail,and the belt truss location,the thickness of the belt truss story has been parametrically analyzed using numerical calculation model.Finally,combining with actual engineering cases,some recommendations are proposed for the design of belt truss considering the utility of"virtual outrigger",which provides a theoretical guidance and design basis for the application of"virtual outrigger"in more projects.

关 键 词：框架-核心筒 伸臂桁架 环带桁架 虚拟伸臂 效率分析 

分 类 号：TU355[建筑科学—结构工程] TU318