2008奥运会羽毛球馆预应力损失对结构体系影响分析

2008奥运会羽毛球馆弦支穹顶结构采用张拉环索的方式进行预应力施工。由于加工制作安装技术难度大,环索与撑杆相连的下节点之间的实际预应力损失比设计取值偏大,引起环索各段索力不均。本文通过在环索节点和撑杆下节点间耦合自由度并增加变刚度弹簧单元来模拟预应力张拉时环索带摩擦滑移,利用此方法可以在有限元模型中模拟施工监测得到的各段环索预应力损失;在此基础上进一步分析了预应力损失对弦支穹顶结构的内力、变形以及整体稳定的影响。研究表明:预应力损失造成径向拉杆内力发生大幅度变化;造成钢网壳内力分布不均匀;对结构的整体变形影响不大,只是使同圈的结构变形不均匀;使结构的整体稳定性能下降20%左右。

Influence of prestress loss on structural behavior of the badminton gymnasium for 2008 Olympic Games

Loop cable tensioning method was adopted in the construction of the badminton gymnasium for 2008 Olympic Games.Due to the processing and installation difficulty,the prestress loss of cable-strut joint is much more than the design value causing the unbalance of cable forces.In this paper,by coupling the degrees of freedom of loop cable joint and brace strut lower joint and adjusting stiffness spring element,the frication sliding of loop cable is simulated.This method can be used in finite element model to simulate accurately the value of the prestress loss in loop cable during tensioning process.Furthermore,the influence of the prestress loss on internal forces,deformation and the overall stability is studied.The study shows that the prestress loss results in wide-range change of the inner force of radial tension bars;non-uniform of inner force of steel shell;narrow change of the overall displacement,non-uniform of the displacement of the same loop members;about 20% decline of overall stability.