既有钢管混凝土提篮拱桥结构刚度退化分析及处治  

Analysis and Treatment of Structural Stiffness Degradation of Existing Concrete-Filled Steel Tubular Basket-Handle Arch Bridge

作　　者：黄建初 王世超 HUANG Jianchu;WANG Shichao(Guangxi Communications Investment Science and Technology Co.,Ltd.,Nanning 530028,China;Guangxi Highway Maintenance Research Center of Engineering Technology,Nanning 530028,China;School of Highway,Chang′an University,Xi′an 710064,China)

机构地区：[1]广西交投科技有限公司,广西南宁530028 [2]广西高速公路养护工程技术研究中心,广西南宁530028 [3]长安大学公路学院,陕西西安710064

出　　处：《世界桥梁》2025年第2期119-125,共7页World Bridges

基　　金：国家自然科学基金青年基金项目(52408505)。

摘　　要：某桥为2跨单孔净跨径126 m的中承式钢管混凝土提篮拱桥,桥梁运营15年后定期检测发现钢纵、横梁连接螺栓松脱和桥面板开裂等病害,静动载试验结果显示拱肋强度满足设计荷载要求,桥梁结构刚度偏低。为了解桥梁结构刚度退化原因,采用有限元法对比分析钢管混凝土脱空和钢纵、横梁连接螺栓松脱2种影响因素下桥梁振动频率、拱顶挠度和桥面挠度变化。结果表明:按现行规范考虑0.95的脱空折减系数,对桥梁振动频率、拱顶挠度和桥面挠度影响不大;钢纵、横梁连接螺栓松脱对桥梁振动频率、拱顶挠度、桥面挠度影响明显,是桥梁结构刚度退化的主要影响因素;综合考虑钢管混凝土脱空和钢纵、横梁连接螺栓松脱的计算结果与荷载试验实测值较接近。对全桥松脱螺栓进行拧紧、裂缝封闭处治后,桥面系结构整体性能得到有效提升,行车振动异响得到较大改善。A bridge is a half-through,concrete-filled steel tubular(CFST)basket-handle arch bridge with two spans of 126 m.Deteriorations,including loose bolted connections between the steel stringers and steel cross beams and concrete slab cracking,were revealed by regular inspections after the bridge had been in service for 15 years.Although the static and dynamic tests demonstrated that the strength of the arch ribs still met the design requirements,the stiffness of the bridge was low.Numerical analysis was carried out to investigate the causes of stiffness degradation of the bridge structure.The focuses were on the debonding of the steel tubes and the infill concrete and the loose bolted connections between the steel stringers and steel cross beams,and the related parameters analyzed included the vibration frequencies of the bridge,deflection of the arch crown and deflection of the deck.The results demonstrate that the debonding of the steel tubes and the in-fill concrete does not exert great influence on the vibration frequencies of the bridge as well as the deflection of the arch crown and the deflection of the deck,when a code-suggested debonding reduction factor of 0.95 is considered,but the influence of the loose bolted connections between the steel stringers and steel cross beams is significant,which is regarded as the primary cause of the stiffness degradation of the bridge.When both the scenarios(the debonding of the steel tubes and the in-fill concrete and the loose bolted connections between the steel stringers and steel cross beams)were taken into account,the calculated results approximate the load test results.After tightening the loose bolts and remedying the cracks,the integral performance of the deck system has been effectively improved,and the abnormal vehicle-induced vibrations have been reduced.

关 键 词：钢管混凝土提篮拱桥 病害 荷载试验 刚度退化 振动频率 位移 有限元法 处治 

分 类 号：U448.22[建筑科学—桥梁与隧道工程] U445.71[交通运输工程—道路与铁道工程]