峡谷大跨径钢桁梁斜拉桥上构施工关键技术

Key Superstructure Construction Techniques of Cable-stayed Bridge with Large-span Steel Truss Girder on Canyon

依托北盘江大桥上构采用边跨顶推+中跨悬拼的总体施工方案,对常用的拖拉式顶推法、楔进式顶推法、步履式顶推法3种顶推工艺做了进一步分析,最终在传统顶推工艺的基础上研发了"钢桁梁节点自适应步履式顶推技术",实现了步履式顶推系统在钢桁梁施工领域的应用;通过顶推姿态可视化监视控制系统,实现了顶推过程中的主动纠偏,保证了长300m、重7 000t边跨钢桁梁顶推施工,大桥线形、精度均满足设计要求,然后对中跨钢桁梁采用平面构架+单件拼装组合架设方案的研究,保证了主跨720m钢桁梁快速、安全实施,为大桥建设创造了效益。

Relying on Beipanjiang Bridge using scheme of the side span push ＋ midspan cantilever assembly,Secondly,it is further analyzed by three kinds of drag-and-drop method,wedge push method and walking push method,and finally developed on the basis of the traditional push technology ＂joint adaptive walking technique for steel truss girder＂,the application of the walking push method in the construction of steel truss girder is realized; Through the push-up attitude visualization monitoring and control system,the active rectification is realized in the process of pushing forward,to ensure a length of 300 m,weight of 7 000 t side of the steel truss girder construction,the line and precision of the bridge meet the design requirements. Finally,through the study of the cross-steel truss girder with a flat frame ＋single-piece assembly combination of erection program to ensure that the construction of steel truss girder with the main span of 720 m is fast and safe,for the bridge to create a benefit.