低施工净空条件下的山区河流大跨度钢桁梁架设方案比选研究

摘要

在山区河流进行桥梁施工相比常规条件更加复杂，当桥梁施工还受到限高影响时，桥梁施工的难度和风险倍增。文中以新建成贵铁路菜坝岷江特大桥钢桁梁架设施工为例，针对该桥施工净空低、山区河流、薄覆盖层等工程特点，提出了3种钢梁架设施工方案，并分别从受力安全、施工难度、经济投入和施工工期等方面进行比选，最终给出本工程的最优施工方案。%The bridge construction over Mountain Streams is much more complicated than conventional construction.When the bridge construction was influenced by aviation limited height,the construc-tion difficulty and risk will be redoubled.In this paper,taking example for the new Caiba Minjiang River Bridge on Chengdu-Guiyang Railway,three construction schemes were proposed for the course characteristic of low clearance during the construction stage,the mountain streams and thin covering layer,etc.After the load bearing safety,the degree of construction difficulty,economic investment and the construction schedules were compared from these three schemes,the most suitable scheme was chosen at the end of this paper.