公路工程

以平面曲线半径R=150 m、横坡i=6%、最大墩高H=91.2 m、桥长L=550 m的钢混组合梁为研究对象，通过考察现场地形地貌及临建情况，研究出在施工现场台架拼装钢主梁并浇筑桥面板形成单片组合梁结构后，再采用架桥机架设单片组合梁的施工方法，该方法可最大程度加快施工进程，满足工期要求；针对先形成单片组合梁结构再架梁的施工方法，研究配套的设计方案，采用结构简支桥面连续的结构型式设计钢混组合梁，使用MIDAS CIVIL有限元软件，特别考虑风荷载、离心力、车道偏载等，分别对施工阶段和成桥阶段的承载力、刚度、抗倾覆稳定性进行了计算分析，各项指标均满足规范要求。对于架桥机架梁喂梁、施工偏载的施工阶段进行了单独的受力分析及稳定性分析，满足规范要求。采用的设计与施工技术对于现场条件受限、顶推施工困难且桥墩较高、不具备搭设临时支墩条件进行吊装施工的小半径、高墩钢混组合梁桥提供了一定的经验及借鉴意义。

By studying the steel-concrete composite girder bridge with plane curve radius R=150 m, transverse slope i=6%, maximum pier height H=91.2 m, and bridge length L=550 m, and investigating the topography and temporary construction of the site, the construction methods studied are as follows, after assembling the steel girder on the construction site and concreting bridge deck to form a single-piece composite beam structure, the single-piece composite beam is erected by the bridge erecting machine.This method can accelerate the construction process to the greatest extent and meet the requirements of the construction period.Aiming at the construction method of first forming single piece composite beam structure and then erecting beam, the supporting design scheme is studied, and the steel concrete composite beam is designed by using the structural type of simple supported beam.Using MIDAS CIVIL finite element software, special consideration is given to wind load, centrifugal force, lane deviation load, etc.The bearing capacity, stiffness and anti-overturning stability of construction stage and the post-construction stage are calculated and analyzed respectively.The calculation results meet the specification requirements.The stress analysis and stability analysis were carried out on the construction stage of installing girder by bridge erector and thecondition of unbalanced load during construction period, which met the requirements of the specification.The design and construction technology of the research provides some experience and reference forthe small radius and high pier steel-concrete composite girder bridge with limited on-site conditions, jacking construction is difficult, the pier is too high to set up temporary piers for hoisting construction.