上海张江双子塔结构设计关键问题

Key issues in structural design of Shanghai Zhangjiang twin towers

上海张江双子塔是由两栋高度及立面相同的超高层塔楼组成,结构高度为298m,采用框架-核心筒-环带桁架的结构体系,为超B级高度超限高层结构。双子塔的主要结构特点是为匹配幕墙立面,外框直柱和斜柱相结合形成交汇及分叉的复杂节点;此外,双塔均设置了两道环带桁架作为加强层,高区核心筒均有斜墙单侧收进。重点介绍外框斜柱承担剪力比、核心筒斜墙性能化设计、交汇及分叉柱的复杂节点设计、黏弹性阻尼器减震方案的可行性等关键问题。采用YJK、ETABS和SAUSAGE等软件进行整体弹性及动力弹塑性分析,并进行抗震性能化设计,对关键及薄弱构件采取针对性加强措施。选取其中一栋塔楼计算结果为例,结果表明:塔楼结构选型及布置合理,具有良好的抗风和抗震性能。

Shanghai Zhangjiang twin towers are composed of two super high-rise towers with the same height and elevation. The 298 m-structural-height twin towers are super class B high-rise structures, and the frame-tube-belt truss structural systems are adopted. The main structural characteristics of the twin towers are that in order to match the building facade, the straight columns and inclined columns of outer frame are combined to form complex nodes of intersection and bifurcation. Additionally, two belt trusses are designed as the strengthening layers for each tower, and step-back of inclined walls are set at one side in the high area of each tower. The key problems were focuses on such as the shear ratio of outer frame inclined columns, the performance-based design of inclined walls, the complex joint design of intersection and bifurcation columns, and the energy-dissipating scheme of viscoelastic damper. The softwares of YJK, ETABS and SAUSAGE were used for overall elastic and dynamic elastic-plastic analysis, and targeted strengthening measures were taken for key and weak components by seismic performance-based design. Taking one tower of twin towers as an example, the results show that the scheme and layout of the structures are reasonable, and the structures have good wind resistance and seismic performance.