Research On Vibration Reduction And Reinforcement Design Of Concrete Filled Steel Tubular Arch Bridge Without Longitudinal Beam

Concrete-filled steel tube arch bridge has been used widely and developed rapidly in China due to superior mechanical properties of concrete-filled steel tube and simple construction steps.However,due to the imperfection of the previous theory and the lack of experience,some early-built concrete-filled steel tube arch bridges mostly never set longitudinal beam and adopt the layout of longitudinal deck system leading to the lack of longitudinal connection of bridge and poor overall stiffness of bridge deck system.Up to now,there are various degrees of diseases,which are mainly manifested in the poor deck system and dynamic performance,especially the vibration problem of bridges under overloads and bridge deck overturning after suspender breaking.Based on a traditionnal concrete filled steel tube arch bridge,three reinforcement schemes are proposed combining with the actual situations in this paper.Using Japanese VG vibration index and ISO2631-1 of evaluation of human exposure to whole-body vibration international standard to analysis the driving comfort of the bridge under before and after reinforcement and under different driving model conditions.Comparing three evaluation results,the optimal scheme to ensure the vibration comfort of the bridge is selected.On this basis,the static and dynamic characteristics and cracking conditions of suspender of the reinforced bridge are analyzed,which proves that the static and dynamic characteristics of the strengthened bridge meet the requirements of the code and the vibration characteristics of the bridge have been improved,as well as the bridge safety after cracking of Suspender is ensured.Local stress is the key link to check the effect of bridge vibration reinforcement.Based on the 1/3 scale local reinforcement model,this paper carries out local reinforcement test,including static load test of local reinforcement model and failure test of local reinforcement model,and establishing ABAQUS model of local reinforcement finite element.Ensur the rationality of detailed stress of reinforcement scheme and verifying the reinforcement worker process through the comparative analysis of the two models.Based on the optimal vibration reduction reinforcement scheme,scale model test and finite element analysis proposed in this paper,static and dynamic analysis,suspender fracture analysis and local reinforcement simulation analysis of the strengthened bridge are carried out,which proved the effectiveness and feasibility of the reinforcement scheme,and is a good reference value for the reinforcement design of other types of bridges in China.