Stress Characteristics Analysis Of Prestressed Concrete Continuous Box Girder Bridge By Bonded Reinforcement

Prestressed concrete continuous box girder bridge is common bridge type in China onaccount of its advantages in mechanics, gentle deflection curve of main girder and drivingcomfort. However, there are many cracks in top plate, web plate, bottom plate, diaphragm plate,and truss plate of box girder caused by flaws in management, design, and construction. Thesecracks badly affect durability safety and normal use of box girder. So it is essential to takeeffective strengthening measures to ensure using function of bridge. Steel plate and CFS isapplied in strengthening engineering of bridge structure because of its advantages of its easyconstruction，and it almost does not increase the size of the original structure. The prestressedconcrete continuous box girder strengthened with steel plate and CFS is studied in finiteelement analysis.According to nonlinear finite element theory, the nonlinear finite element of prestressedconcrete continuous box girder is build with Midas FEA. Then the methods of building modelare used successfully, including of meshing, element types, parameter selection boundaryconditions and convergence criteria, so that the finite element modeling method of simulationof whole process of the destructive test of the box girder could be obtained.Based on the successful simulation of the box girder, though comparative analysis, it isproved that affixed reinforcing could improve ultimate bearing capacity of box girder and delaythe coming out of cracks. Theoretical basis of strengthening design of steel plate and CFS isprovided. The concrete continuous box girders model of different prestress loss are built,though comparative analysis it is proved that the effect of strengthening to prestressed lossbridge with CFS is fine.