大型开闭屋盖结构极端状况研究

Study on extreme cases for large-span retractable roof structure

以南通市体育会展中心主体育场为工程背景,对开闭式结构进行非常规工况下的受力分析,考察结构是否会因意外事件引发连续性破坏。设定了活动屋盖非对称运行、单根牵引钢索破断、活动屋盖因机电控制设施失效发生整体下滑并引发冲击作用等3种非常规工况。分析中采用了动力方法,考虑了几何大变形和冲击作用的影响。分析表明,活动屋盖非对称运行下结构仍具有较高的承载力,单根钢索的破断不致引起严重的结构内力重分布和大变形而引发连续性破坏,但活动屋盖的整体下滑冲击对结构极为不利。非常规工况作为非安全因素目前尚难以纳入基于可靠度理论的现行结构设计规范中,工况的设定应充分考虑结构的特殊性并进行相应的分析和评价。

The retractable roof structure of the stadium located in Nantong Sport Center under assumed abnormal loads was analyzed to investigate the risk of progressive failure due to accidental events. Three events were eonsidered, ineluding unsymmetrieal motion of movable roofs, fraeture of one traction eable, as well as slippage and impaet of movable roof due to malfunction of eleetmmeehanieal devices. The effeets of geometfie large deformation and impact aetion were taken into aeeount in dynamie analysis. The study shows that main stmeture earl preserve its bearing eapaeity under unsymmetrieal motion of movable roof or fraeture of traetion eable, but the slippage and impaet aetion of whole movable roof may be detrimental to the strueture. Abnormal eases, which are beyond the framework of the eurrent design eodes based on struetural reliability theory, should be presumed according to structural specialties and then be evaluated for structural safety.