大跨扣索悬臂浇筑拱桥索力确定及优化研究  

Research on the Determination and Optimization of Cable Forces for Large⁃Span Cable⁃Stayed Cantilever Casting Arch Bridges

作　　者：魏成策 WEI Chengce(China Railway 17th Bureau Group Urban Construction Co.Ltd.,Guizhou Gui′an 550025,China)

机构地区：[1]中铁十七局集团城市建设有限公司,贵州贵安550025

出　　处：《铁道建筑技术》2024年第9期132-136,共5页Railway Construction Technology

基　　金：中国铁建股份有限公司科技研发计划项目(2022-C18)。

摘　　要：大跨度悬臂浇筑钢筋混凝土拱桥扣索索力优化对拱桥成桥质量至关重要。依托高原峡谷地带主跨200 m钢筋混凝土拱桥悬臂浇筑施工项目,通过有限元软件建立三维数值模型,采用最小弯曲能量法求得了一组扣索索力。进一步基于影响矩阵法,用有限元软件中未知荷载系数功能对扣索索力进行优化,并将优化前后的索力分布、拱圈弯矩、应力等指标进行对比。研究表明:最小弯曲能量法确定的索力变化,随着扣索长度的增加,扣索索力总体呈增大趋势,且越靠近拱顶,索力变化幅度越大;通过有限元软件优化后的索力分布特征与优化前基本一致,但优化后的索力增幅显著,安全富余度更大,尤其是靠近拱顶附近;优化后的索力组合有效降低了拱圈的弯矩、上下缘应力,拱桥整体应力分布得到显著改善。本研究可为类似工程提供一定的借鉴。The optimization of cable tension in large⁃span cantilever casting reinforced concrete arch bridges is crucial for the quality of the completed bridge.This article relies on the cantilever pouring construction project of a reinforced concrete arch bridge with a main span of 200 m in the plateau canyon area.A three⁃dimensional numerical model is established through finite element software,and a set of cable tension is obtained using the minimum bending energy method.Further based on the influence matrix method,the unknown load coefficient function in finite element software is used to optimize the cable force of the buckle,and the cable force distribution,arch bending moment,stress and other indicators before and after optimization are compared.Research has shown that the variation law of cable force determined by the minimum bending energy method:as the length of the cable increases,the overall trend of cable force increases,and the closer it is to the arch,the greater the amplitude of cable force change.The distribution characteristics of cable forces optimized by finite element software are basically the same as before optimization,but the increase in cable forces after optimization is significant,and the safety margin is greater,especially near the arch top.The optimized cable force combination effectively reduces the bending moment and upper and lower edge stress of the arch ring,and significantly improves the overall stress distribution of the arch bridge.This study can provide some reference for similar projects.

关 键 词：悬臂浇筑拱桥 最小弯曲能量法 未知荷载系数 索力优化 

分 类 号：U448.22[建筑科学—桥梁与隧道工程]