Simulation Analysis And Method Of Calculation Of Strengthening Prestressed Concrete T Beam

Prestressed concrete structure has many advantages,such as high structure stiffness,small deformation,less expansion joints,easy to maintenance, strong seismic capacity, driving comfort and so on.So,it has been widely applied in highway bridge.The prestressed concrete bridges in China are more than 75 percent of all the beidges.At present, many old bridge in China have been defects in different degrees,such as creaks, inadequate carrying capacity and so on.These often tesult in traffic congestion even interruption, stintural damage and serious the national economy loss, Causing inconvenience to people's life. Optimization of strengthening schemes of bridge has been became thecurrent research focuses. But now, for large scale prestressed concrete beam, there are few researches on it. Thus,it has practical significance that study on comparison and analysis of strengthen methods for prestressed concrete T beams.This paper analyzes the common defects of bridge structures. with large-scaled finite element analysis software-ANSYS, it simulates the performance of prestressed concrete T beams, studying the strengthening effect of five types of measures, such as carbon fiber adhesion method, steel plate adhesion method, section-enlarging method and steel plate/ carbon fiber plus section-enlarging method. It analyzes their strengthening effects, including ultimate flexural capacity, deflection, rigidity, ductility and crack propagation, and summarizes their advantages and disadvantages. In addition, it compiles a program in Mathcad for the calculation of the flexural capacity of prestressed concrete members, and the computed result it used to verify the reliability of finite element simulation.The study indicates that, section enlargement plus steel plate adhesion has the best effect in increasing the flexural capacity and rigidity, restraining the development of cracks, but it may reduce the ductility of the beam; whereas carbon fiber adhesion method and steel plate adhesion method can improve ductility of T-beams, for beams with great depths, carbon fiber adhesion method hardly has effect, hence must be used carefully in practice; Moreover, the paper found that, there are some faultinesses in several formulas in the Specifications for Strengthening Design of Highway Bridges. Therefore, this paper puts forth a new way to get flexural capacity exactly and rapidly, i.e., by coding program in Mathcad, which can be extended to more common cases.