葵花形连续拱桥模架支撑体系风险控制技术研究  

Research on Risk Control Technology of Formwork Support System of Sunflower-shaped Continuous Arch Bridge

作　　者：韩强 Han Qiang(Beijing Municipal Road and Bridge Co.,Ltd.,Beijing 100045,China)

机构地区：[1]北京市政路桥股份有限公司,北京100045

出　　处：《市政技术》2024年第12期182-189,共8页Journal of Municipal Technology

基　　金：北京市政路桥股份有限公司科技项目。

摘　　要：广州市九龙湖大桥是一座三跨葵花形连续拱桥,葵花形连续拱桥与传统拱桥在形式上存在巨大差异,其受力性能也较为复杂,目前对其结构体系的力学性能研究还不够全面。该桥在施工过程中,需要分阶段浇筑主拱、腹拱以及拱上结构,因此支架会分步搭设和拆除,这将涉及结构体系的转换。采用不同的施工方法和工序可能会导致临时支撑体系和桥梁主体结构在应力和位移上出现较大差异。若应力或位移超过临界限值,将存在较大的安全风险。为研究合理的施工工序,控制施工过程风险,通过有限元分析法对支架的搭设和拆除全过程进行数值模拟,提出了安全可靠的施工工序。结果显示:葵花形连续拱桥结构整体施工完毕后,拆除主拱圈下方支架,会产生应力集中释放,导致横截面有一定的开裂风险;而在拱上纵向主梁浇筑前,先将主拱圈下方支架拆除以释放部分结构变形,对于控制主拱圈线形和横截面应力更为有利。研究成果对于类似拱桥的支架搭设和拆除施工具有借鉴意义。The Jiulong Lake Bridge in Guangzhou is a three spans sunflower-shaped continuous arch bridge.The sunflower-shaped continuous arch bridge has great difference from the traditional one in form,and has complex mechanical performance.At present,there isn’t enough comprehensive research on the mechanical performance of structural system.During the construction of the bridge,the main arch,abdominal arch and the structure above the arch need be poured by stages,so the support will be erected and removed step by step,which involve transformation of the structural system.Different construction methods and procedures will cause great differences in stress and displacement between the temporary support system and the main structure of the bridge.If the stress or displacement exceeds the critical limit,there will be a great safety risk.In order to study the reasonable construction process and control the risk,the whole process was numerically simulated by finite element analysis method,and the safe and reliable construction process was proposed.The results show that after the overall construction,the removal of the support under the main arch ring will produce stress concentration release,resulting in a certain risk of cracking in the cross section;Before pouring the longitudinal main beam on the arch,the support under the main arch ring should be removed to release some structural deformation,which is more favorable for controlling the alignment and cross-sectional stress of the main arch ring.The research results have reference significance for similar arch bridge support erection and demolition construction.

关 键 词：葵花形连续拱桥 支架搭拆工序 结构体系转换 施工风险 

分 类 号：U448.22[建筑科学—桥梁与隧道工程]