伸臂桁架体系和梯式连梁体系的高层建筑抗震性能评估  

Evaluation of Seismic Performance for Outrigger System and Ladder System in High Rise Buildings

作　　者：Yahia Halabi Wael Alhaddad 许浒[1] 余志祥[1] Yahia Halabi;Wael Alhaddad;Hu Xu;Zhixiang Yu(Department School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;Department of Structural Engineering,Tongji University,Shanghai 200092,China)

机构地区：[1]西南交通大学土木工程学院,成都610031 [2]同济大学结构工程系,上海200092

出　　处：《钢结构（中英文）》2021年第8期1-19,共19页Steel Construction（Chinese & English）

基　　金：the National Key Research and Development Program of China under Grant No.2016YFC0802205;the Department of Science and Technology of Sichuan Province under Grant No.2019YJ0221.

摘　　要：卓越的抗震性能一直是高层建筑结构设计不断追求的目标,而抗侧力体系则是实现该性能目标的关键因素。伸臂桁架体系作为目前最常见的抗侧力结构体系之一,广泛应用于各地标高层建筑中。然而,伸臂桁架体系的力学性能受桁架布设位置、拓扑形式、施工工序等因素影响,同时还存在整体结构竖向刚度不规则问题,因此,其实际抗震性能和优化途径值得关注。梯式连梁体系是一种较为新颖的抗侧力结构体系,每一层均设置水平连梁连接核心筒与巨柱,与伸臂桁架体系在某些楼层处形成集中刚度相比,其抗侧刚度分布更加均匀。为了对比上述两种抗侧力结构体系的抗震性能,以一栋80层的建筑模型作为研究对象,利用ETABS有限元程序建立其数值模型,并采用基于性能的抗震设计方法开展计算分析。按沿高度方向共设置4榀伸臂桁架进行设计,综合考虑结构自重、基底弯矩、基底剪力、层间侧移、筒体弯矩等多种因素,明确了伸臂桁架布设位置,分别是17~18层、32~33层、46~47层和62~63层。此外,建立了4种用钢量相同但几何拓扑形式不同的伸臂桁架模型,通过对比整体结构的自振周期以及在多遇地震和设防烈度地震作用下的基底剪力、弯矩和层间位移等地震响应,选取了最优的拓扑形式。在此基础上,利用等效刚度原则建立了梯式连梁体系数值模型,明确了连梁的截面形式和设计参数,确保其与伸臂桁架体系模型具有相同的整体抗侧刚度。采用FEMA 365指南中的构件性能曲线特征值以及性能水准判别准则,选取7组天然地震动和2组人工地震动记录作为输入参数,考虑三向地震作用,分别对伸臂桁架体系模型、梯式连梁体系模型和纯筒体体系模型开展了不同地震烈度下的非线性动力时程分析。计算结果显示:1)在位移响应方面,与纯筒体体系相比,伸臂桁架体系和梯式桁架体系Excellent seismic performance of high-rise building is a continuous destination in structural engineering,that highly relies on the lateral load resisting system.As one of the most common lateral load resisting systems,the outrigger system is widely applied to skyscrapers.However,its mechanical properties are affected by the truss location,the topological form as well as construction process,in addition,the irregular vertical stiffness of the entire building occurs.Therefore,the actual seismic behavior and optimization methods are worthy paying attention to.The ladder system is a novel lateral load resisting system,in which the horizontal beams are set to connect the mega columns at each floor,resulting in a more uniform vertical stiffness compared with the outrigger system.In order to compare the seismic performance between the above two systems,the numerical models of 80-story building were established by means of the finite element program ETABS,and the performance-based seismic design method is adopted to carry out calculation and analysis.For the outrigger system,four levels of steel outrigger trusses were set along the height,and the specific locations that floor 17-18,floor 32-33,floor 46-47,and floor 62-63,respectively,were determined by considering the multiple factors including structural weight,base moment,base shear,inter-story drift,and core moment.In addition,the optimum topology of the outrigger truss was selected out of four different trusses’topologies with the same steel consumption according to the favorable natural period and the global response of the structure,such as base shear,bending moment and inter-story drift under the action of frequent and moderate earthquakes.Subsequently,the ladder system was generated based on the principle of the equivalent lateral stiffness with the outrigger model,and the cross section as well as the design parameters were presented.Nonlinear dynamic time history analysis was carried out to compare the global and components’performance between the outrigger

关 键 词：伸臂桁架体系 梯式连梁体系 基于性能抗震设计 非线性动力时程分析 桁架拓扑优化 

分 类 号：TU973.31[建筑科学—结构工程]