上承式钢管混凝土拱桥桥道系病害分析和加固

Disease Analysis and Reinforcement of Superstructure of Concrete-filled Steel Tube Arch Bridge

为了研究在役上承式钢管混凝土拱桥桥道系结构病害产生的原因,梳理桥梁历年养护情况,建立全桥有限元模型和上部结构单梁模型,进行影响因素分析。分析表明:T梁承载能力下降导致大量U型裂缝产生,主拱圈温度作用下的变形、桥道系自身整体性不足导致桥面铺装开裂。提出一种改进的体外预应力布置方式以提升T梁承载能力,并利用有限元分析验证其加固效果,采用超高性能混凝土重做现浇层和T梁横隔板包钢增强桥面铺装韧性和桥道系整体性。

In order to study the causes of structural defects in the superstructure of the in-service concrete-filled steel tube arch bridge,the maintenance situation of the bridge over the years was sorted out,the finite element model of the whole bridge and the single beam model of the superstructure were established,and the influencing factors were analyzed.The results show that the decrease of T-beam bearing capacity leads to a large number of U-shaped cracks,the deformation of the main arch ring under the action of temperature and the lack of integrity of the superstructure lead to the bridge deck pavement cracking.An improved external prestressed arrangement is proposed to enhance the load bearing capacity of T-beam,and its reinforcement effect is verified by finite element analysis.UHPC is used to redo the cast-in layer and T-beam diaphragm steel to enhance the toughness of bridge deck and the integrity of superstructure.