北京大学体育馆钢屋盖预应力桁架壳体结构分析的几个关键问题

Several key issues of structural analysis of prestressed steel truss shells roof of Beijing University gymnasium

本文介绍了2008年奥运会乒乓球比赛馆———北京大学体育馆预应力桁架壳体钢屋盖结构分析的三个关键问题:初始态预应力度的确定、地震作用下屋盖的地震响应分析以及屋盖的极限承载力分析。所有问题均采用非线性有限元分析,其中屋盖的极限承载力采用弹塑性非线性有限元进行分析,同时考虑了几何非线性和滑动支座滑动引起的支承条件的非线性变化。分析结果表明,预应力拉索和滑动支座的积极应用,使屋盖结构成为自平衡体系,提高了屋盖结构的效率,减小了下部支承结构的设计难度;屋盖的极限承载力取决于支座立柱、中央刚性环和屋盖支撑的强度和刚度。

A new-style hybrid tension structure with prestressed truss shell system, was applied in the steel structural roof of the Beijing University gym Table Tennis Gymnasium for the 2008 Olympic Games. Three key technical problems in structural analysis are introduced in this paper. These problems include the determination of initial pre-tension force, seismic response analysis of the roof structure and ultimate capacity analysis. Nonlinear analysis of the problems is realized using ANSYS and SAP2000 packages. Geometric nonlinearity, material nonlinearity and support condition nonlinearity caused by the slide bearing are considered in the analysis of ultimate capacity. The analytical results show that through active application of the prestressed cables and sliding bearings, a self-balanced roof structure is possible, which improves the efficiency of the roof and simplifies the design for the supporting system. The ultimate capacity of the roof structure depends on the strength and rigidity of the supporting columns, central rigid ring and the roof brace system.