大跨度人行天桥钢箱梁两节段拼装技术

Two Section Assembling Technology of Steel Box Girder of Long Span Pedestrian Bridge

新新公路改扩建工程为省道S118线的一段,是广州市增城区两个经济重镇新塘与中新之间的重要通道。该项目共有5座钢箱梁人行天桥需要修建,由于该路段交通量非常大,且要满足边施工、边通车的客观要求,导致人行天桥无法封闭施工。为确保人行天桥的施工进度、质量和安全,将原设计分5节段梁工厂加工后运至人行天桥下吊装位置利用临时支墩吊装拼接的方案,优化为分两节段在工厂加工并设置预拱度后运至人行天桥下吊装位置利用临时支墩吊装拼接的方案。通过优化加工拼装方案,加快了人行天桥的施工进度,减少了工地焊缝的数量,降低了钢箱梁焊接受外界不利因素的影响,缩短了拼装占道施工的时间,确保了交通安全。

The reconstruction and expansion project of Xinxin Highway is a section of Provincial Highway S118,which is an important passage between Xintang and Zhongxin,two important economic towns in Zengcheng District,Guangzhou.There are a total of 5 steel box girder pedestrian bridgesto be built in this project.Due to high traffic volume of this section and the principle of opening to traffic while construction is being carried out,the pedestrian bridge cannot be constructedwithclosed traffic.In order to ensure the construction progress,quality and safety of the pedestrian overpassbridges,the original design has been divided into 5 segments that have beenmanufactured in the factory and transported to the lifting position under the pedestrian overpass bridgeusing temporary support piers for lifting and splicing.The optimization hasbeendetermined to divide them into two segments that have beenmanufactured in the factory with pre-camber before being transported to the lifting position under the pedestrian overpass bridgeusing temporary support piers for lifting and splicing.By optimizing the processing and assembly plan,the construction progress of pedestrian overpasses has been accelerated,the number of welding seams on the construction site have been reduced,the impact of external adverse factors on the welding of steel box beams has been reduced,the construction time of assembly and road occupation has been shortened,and traffic safety has been ensured.