钢-UHPC组合梁自锚式悬索桥力学性能与经济性分析  

Mechanical Performance and Economic Analysis of Self-anchored Suspension Bridge with Steel-UHPC Composite Girder

作　　者：贺耀北 邵旭东[1] 张欣 赵华[1] 王永[3] HEYaobei;SHAO Xu-dong;ZHANG Xin;ZHAO Hua;WANG Yong(School of Civil Engineering,Hunan University,Changsha 410082,China;Hunan Provincial Communications Planning,Survey&Design Institute Co.,Ltd.,Changsha 410008,China;School of Economics and Management,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]湖南大学土木工程学院,湖南长沙410082 [2]湖南省交通规划勘察设计院有限公司,湖南长沙410008 [3]北京交通大学经济管理学院,北京100044

出　　处：《桥梁建设》2021年第1期51-57,共7页Bridge Construction

基　　金：湖南创新型省份建设专项项目(2020RC3081);湖南省科技重大专项项目(2017SK1010)。

摘　　要：为了解钢-UHPC组合梁自锚式悬索桥的受力性能及经济性,以益阳青龙洲特大桥为背景,建立全桥空间有限元杆系结构模型及组合梁局部有限元模型,研究钢-UHPC组合梁的抗弯承载能力、UHPC桥面板的抗裂能力,并与常规钢-混组合梁经济性进行对比。结果表明:在最不利组合下,组合梁箱形钢主梁、钢横梁的最大拉应力分别为206.3MPa、212.9MPa,小于钢材抗拉强度设计值;正截面承载能力状态UHPC桥面板上、下缘最大压应力分别为33.76MPa、24.4 MPa,安全系数达1.85,结构受力安全;频遇组合下UHPC纵肋下缘最大拉应力为16.73MPa,为初裂应力的89%,抗裂性能良好。桥面板采用UHPC结构时,比采用普通混凝土结构增加了163%的建造费用,但综合结构变化后的其他主要分部工程,总体建造成本仅增加2.0%,考虑到UHPC结构优异的力学性能及耐久性,钢-UHPC组合梁方案经济上较为合理。To investigate the mechanical performance and economy of self-anchored suspension bridges with Steel-UHPC composite girders,the Qinglongzhou Bridge in Yiyang is taken as a study case.Based on which,the spatial finite element model of the whole bridge and local finite element model of the composite girders were built up to study the flexural strength of the steel-UHPC composite girder and the crack resistance of the UHPC slabs.And the economy of the steel-UHPC and steel-normal concrete composite girders was compared.The results show that the maximum tensile strengths of the steel box girder and the steel cross beam are 206.3 MPa and 212.9MPa,respectively,under the most adverse load combinations,which are less than the design flexural strength of the steel.When the UHPC slabs are in the normal cross-section load bearing state,the maximum compressive stresses in the upper and lower flanges are 33.76MPa and 24.4MPa,respectively,with safety coefficient reaching up to 1.85,proving that the structure is safe.Under the frequent load combinations,the maximum tensile strengths in the lower flange of the UHPC longitudinal rib is 16.73MPa,89%of the initial cracking stress,indicating that the crack resistance of the UHPC ribs is great.Although using UHPC makes the construction costs increase by 163%,the total construction costs are only increased 2%,due to the changes of other components.Given the excellent mechanical property and durability of UHPC structures,the steel-UHPC composite girder solution is rational from an economic perspective.

关 键 词：自锚式悬索桥 钢-UHPC组合梁 桥面板 超高性能混凝土 应力 经济性 有限元法 

分 类 号：U448.25[建筑科学—桥梁与隧道工程] U443.35[交通运输工程—道路与铁道工程]