Study On Diagnosis And Treatment Of Prestressed Concrete Continuous Small Box Girder Bridge

Taking the small box girder of Renchi freeway as the research object,combined with some small box girder bridges in the actual project,the diseases of small box girder bridge are summarized and analyzed.The type and frequency of the disease and the overall situation of the bridge are summarized,and the corresponding finite element model is established to study the causes of the typical disease of the small box girder bridge and the mechanism of its occurrence,and to evaluate the effect of the disease on the mechanical performance of the bridge.This paper analyzes and compares the reinforcement efficiency of commonly used bridge reinforcement methods,and finally summarizes the treatment methods and maintenance suggestions for small box girder bridges.The main contents of this paper are as follows:(1)The paper summarizes the disease types of small box girder bridge on Renchi Expressway,and makes a detailed analysis of the crack shape,crack location and crack width of the bottom and web of the main girder.(2)In this paper,the causes of the disease of small box girder bridge are analyzed.The stress of main girder during the construction of small box girder is calculated by finite element software.The stress state of main girder and the change of support reaction force are analyzed in detail after the support of 4*30m and 4*20m small box girder bridge is empty.(3)This paper analyses the effect of different types of damage on the stress of the main beam,such as calculating the effect of longitudinal cracks in the bottom plate and web on the internal force of the main beam,and analyzing the effect of corrosion of the prestressing steel bundle on the stress and deformation of the small box girder.(4)This paper summarizes the treatment methods of small box girder bridge diseases,and puts forward maintenance suggestions for the diseases of small box girder bridge in Renchi Expressway.The reinforcement design of bridge with insufficient prestressing force is carried out,and the reinforcement efficiency of different reinforcement methods is analyzed.