【提要】  对上海铁路南站主站屋新型大跨度钢屋盖结构的抗震性能进行了研究。通过有限元分析,研究了影响此类屋盖结构动力特性的不同因素。得出的结果有：预应力效应影响屋盖结构的振型频率分布；下部混凝土结构与上部屋盖的共同工作效应相当于为屋盖提供了刚度较大的弹性支座；几何非线性特性影响不显著。在时程分析基础上,研究了多维地震输入对屋盖地震响应的影响,指出内柱为屋盖结构的一个较薄弱部位；给出了拉索预应力的初始设计值；并通过时程分析,验证了该预应力设计值可以保证拉索体系在多遇和罕遇地震下均能够正常工作。
【关键词】  有限元分析  大跨度钢屋盖  多维地震输入  时程分析
Seismic Analysis of the Newstyle Longspan Steel Roof Structure of Shanghai South Railway Station/Guan Haitao1,Zhou Jianlong2,Wang Jun3,Huang Dingye1,Wang Dasui2(1 Department of Building Engineering, Tongji University,Shanghai 200092,China； 2 East China Architectural Design & Research Institute,Shanghai 200002,China；3 China Academy of Building Research,Beijing 100013,China)
Abstract:The aseismic behavior is studied for the newtype and longspan steel roof structure of the main building of Shanghai South Railway Station. Factors that affect the dynamic features of the roof are studied by means of FEM analysis. Results show that the prestressing effect has influence on mode distribution, the interactive effect between the supporting structure and the roof is similar to an elastic support with high stiffness under the roof, and the large deformation effect is negligible. On the basis of time history analysis, the roof response to multiple earthquake excitations is studied and the inner columns are found to be a comparatively weak part. The prestressing force of cables is calculated and the validity of the cable system during frequently occurred and seldomly occurred earthquake is proved by time history analysis.
Keywords:FEM analysis; longspan steel roof; multiple earthquake excitations; time history analysis