大跨度坦拱桥钢结构安装支架结构的计算分析

Computation Analysis of Supporting Frame for Steel Structure Installation of Large-Span Flat Arch Bridge

宁波市澄浪桥主桥是一大跨度坦拱桥,其主桥钢结构安装施工采用少支架方案。由于施工期间通航净空等要求,临时支架轨道梁的梁高受到限制。在分析其承受主拱结构安装荷载时,必须考虑已安装钢桥面结构的共同受力。利用MIDAS结构分析软件,建立主桥结构与临时支架结构共同作用的计算模型,分析施工过程整个结构体系受力情况。结构分析结果表明,施工过程中主桥结构和临时支架结构均是安全的。

The main bridge of Ningbo Chenglang Bridge is a large-span flat arch bridge,and the scheme of its steel structure installation adopts less number of supporting frames.Due to navigation clearance requirement during the construction,the height of rail girder of supporting frame is limited.When analyzing the structural behavior of the girder under loads caused by the main arch structure erection,it needs to consider the effect of taking loads by the installed steel deck together.This paper uses MIDAS structural analysis software to create the computation model considering co-interaction between the main bridge and the frame.The model has included whole construction stage and different loading cases,and the structural behavior of whole structure system can be analyzed by using this model.The analysis results show that both the main bridge and the temporary supporting frame are structurally safe during the construction.