The Application Of External Prestressed Technique In Continuous Beam Bridge Reinforcement

In tne morden China, with the economic develop rapidly,the traffic plays an important role in economy is self-evident. According to statistics, the disease of China’s existing highway bridge is shocking. The diseases of highway bridges can not be ignored, appropriate measures must be taken to ensure the health of highway, so traffic can be smooth.In order to reinforce the bridge,we must identify the reasons so as to choose the best method.The first, this paper introduces the defect of concrete continuous beam bridge and its disease, according to the disease to analyze the causes,in order to select right method to reinforce the bridge. On the basis of this, introduces commonly used method of bridge reinforcement,and discusses the advantages and disadvantages of various methods and its principle of selection.Among the many bridges strengthened method, as a kind of active reinforcement method,external prestressing reinforcement particularly suitable for the reinforcement of concrete continuous beam bridge. This paper introduces the calculation schema of reinforcingt beam bridge by external prestress,explains the reinforcement calculation theory, studies the stress increment and prestress loss combined with the design of external prestressing reinforcement.Based on the discussion in theory,we study the general external prestressing system and the technology of reinforcement.At last, combining theory with engineering project,based on the damage simulation,using the finite element software MIDAS to make an external prestressing design of reinforcing the concrete continuous box beam bridge. Through the analysis of calculation, comparising the indexes before and after reinforcement of bridge, in order to prove the effectiveness of external prestress.In order to control the process of construction and ensure the effect of reinforcement,we discusses the construction monitoring plan.Through the field measured data, proves the validity of the construction monitoring, and prove the validity of external prestresse.