Study On External Prestress Reinforcement Technology Of Reinforced Concrete Simple Supported T-beam Bridge

With the rapid economic development,our country highway reconstruction will be the main melody of highway construction in the future,the comprehensive treatment of the original bridge diseases,restore the using performance of original bridge expansion project is an important task,as of the end of 2018 the total number of more than one million Bridges in China,the span of iconic thousands of meters of cable-stayed bridge and suspension bridge in the half of the world,and there are a variety of diseases,bridge bearing capacity does not meet the requirements for operating load proportion is as high as 15%,in order to ensure the operation safety of the structure of the bridge,it is urgent for the modification of the old bridge reinforcement.External prestressing strengthening technology with the development of the prestressed technology to get a number of engineering application,the externally prestressed reinforcement is a method of active reinforcing Bridges,with reinforcing cycle is short,simple construction,strengthening effect is obvious,can greatly improve the stress state of the bridge,and many other characteristics are widely used in actual reinforcement engineering.Based on the reinforcement project of yichunbei bridge,this paper uses external prestress technology,which provides guidance for the reinforcement work of the bridge,and further advances the application of external prestress technology in other practical reinforcement work.The main research contents include the determination and application of the limit stress of external prestress,the determination of the calculation method of external prestress design,the calculation of the position and number of steering block,and the finite element analysis with material component linear.The concrete reinforcement of yichunbei bridge includes the comparison and determination of the reinforcement scheme,the checking of the bearing capacity of the original girder structure,the tension limit stress and the appropriate tension control stress,the estimation of the prestress loss,the estimation of the prestress reinforcement and the checking calculation of the structure of the bridge.ANSYS finite element software was used to analyze the influence of the layout of prestressed tendon and steering block on the reinforcement effect,and the material nonlinearity was considered in the analysis to find an ideal beam distribution scheme.After the implementation of the external prestress reinforcement scheme of yichunbei bridge,the results show that the reinforcement effect is remarkable,which obviously improves the bearing capacity of the bridge structure and reduces the stress amplitude.The feasibility,reliability and safety of external prestressing technology in bridge reinforcement are verified,which can provide reference for the reinforcement and maintenance of similar Bridges.