Research On Reinforcement Design Method Of Existing Prestressed Concrete T Shaped Rigid Frame Bridge

Because T shaped rigid frame bridge has many advantages like force clear, construction of fast, no need to set bearing beams between the piers etc,so in the eighties and nineties of the 20 th century, the designers like this architecture when they design bridges and many T shaped rigid frame bridges were built in our country. After ten years or decades of traffic operations, there were a lot of diseases and damages in the T shaped rigid frame bridge built in the early age because of severe overloading of vehicles, improper maintenance and other reasons. These diseases make the Carrying capacity can’t meet the increasing traffic demand.Combined with our application experience of T shaped rigid frame bridge and the actual operating conditions, this paper research on the reinforcement technology of existing prestressed concrete T-shaped rigid frame bridge were studied on the basis of the results of previous studies.This paper described the development of T rigid bridge in our country and external, and analyzed the mechanical characteristics and the various problems of the bridge. Then this paper summarized research status of reinforcement technology of T shaped rigid frame bridge and the common methods used in the strengthening works.Taking Malan Bridge as an example, we made a comprehensive visual inspection including superstructure, substructure, bearings, deck system and accessory structures etc.Through the examining the results of each component, we gave a technology assessment state of the bridge. On this basis, We also made static and dynamic load test to assess the actual carrying capacity of the bridge.We did reinforcement work for the Malan Bridge based the external prestressing reinforcement integrated methods and calculated the internal forces of the beam being under the external prestressing alone. This paper checked the main bridge capacity, stress and deflection etc after the using external prestressing reinforcement and then compared the force status of the beam before.Based on the detection of disease and Carrying capacity assessment of old bridges, this paper presented a new method of reinforcement. This new method used the steel box girderbeams to instead the suspended beam and changed the continuous T-frame bridge into suspended beam. And then analyzed stress of the beam and then compared the force status of the beam with before. Through the finite element model the paper verified the feasibility of this reinforced method.