山区大跨径悬索桥加劲梁型式研究和比选

Stiffening Girder Type Study and Comparison for Long-Span Suspension Bridges in Mountainous Region

云南普宣高速公路普立特大桥位于构造剥蚀、侵蚀深切峡谷地貌区,拟采用628m单跨悬索桥方案。为选择经济可行的加劲梁方案,对钢箱加劲梁和钢桁加劲梁的适用性进行研究和比选,重点从施工角度对钢箱加劲梁方案可行性及经济性进行论证。研究表明:钢箱加劲梁片状半成品和钢桁加劲梁片状半成品及杆件都能顺利运输至现场,宣威岸可设置加工拼装场地,并按工厂制作要求进行质量控制,节段能顺利起吊安装,2种方案均可行;从施工风险、耐久性及结构整体受力特性、工程造价等方面进行比较,最终确定该桥采用钢箱加劲梁方案。

The Puli Bridge carries part of the Puyi Expressway in Yunnan province. Due to the fact that the bridge is located in the canyon area featuring tectonic denudation and deep erosion, the proposed scheme is a 628 m long single span suspension bridge. To select an economical and applicable stiffening girder scheme, the feasibility of the steel box stiffening girder and steel truss stiffening girder was studied and compared, with the emphasis on the argumentation of the feasi- bility and the economy of the steel box stiffening girder scheme from the perspective of construc- tion. The study shows that the semi-finished pieces of the steel box stiffening girder and those of the steel truss stiffening girder and the chord members are all able to be transported to the site. The assembly yard can be built on the bank in Yiwei side, the quality is controlled in accordance with the fabrication requirements in the factory and the segments should be lifted and installed smoothly, and the two schemes are all feasible. However, it is finally determined that the steel box stiffening girder scheme be adopted for the bridge, considering the construction risk, durabili- ty, the overall load bearing capacity of the structure and project costs.