新广州站索拱结构屋盖体系连续倒塌分析

Progressive collapse analysis of cable-arch structures of the New Guangzhou Railway Station

以新广州站索拱结构屋盖体系为对象,对大跨度空间结构的连续倒塌分析方法进行了研究。利用基于概念判断的敏感性分析方法分析了单榀索拱结构的重要构件。对整体结构的重要构件及其几何位置分布、整体结构中空间作用的分布情况进行了讨论。采用变换荷载路径法(AP法)对该屋盖结构的抗连续倒塌性能进行了评估,并对比了AP法中线性动力计算和静力计算的结果。分析结果表明:静力计算结果偏于保守,而对于含有预应力拉索的结构体系,应考虑构件意外失效前整体结构的初始状态。新广州站屋盖结构体系具有较好的抗连续倒塌性能,该工程采用的新型空间索拱结构及巨型桁架是提高该结构体系抗连续倒塌能力的有效措施。索拱中采用的双索设置增加了正常使用情况下换索的可行性。

The cable-arch structure of the New Guangzhou Railway Station was analyzed to discuss the progressive collapse of long-span space structures. Based on conceptual estimate, the sensitivity analysis method was used to choose the important components of single piece of cable-arch structure. The important components of the whole structure and their geometry distribution and the spatial action of the whole structure were discussed. The alternate path method was used to evaluate the resistance to progressive collapse of the roof structure and the results of dynamic analysis and static analysis were compared. The results show that the static analysis is conservative, and initial state of whole structure before elements disabled should be considered for structures with prestress cables. It can be concluded that the roof structure of the New Guangzhou Railway Station has good resistance to progressive collapse. The new kind of cable-arch structure and huge trusses improve the resistance to progressive collapse. And the cable can be replaced under serviceability state for cable-arch structures with double cables.