The Stress Analysis Of Unbonded Prestressed Concrete Simply Supported Small Box Girder

On account of its excellence, unbonded prestressed concrete structure have widely used inbuilding, but its use in bridge is rare to this day. It is necessary to search the speciality ofunbonded prestressed concrete structure using in bridge structure. Based on Qi-Cha Road A-Lun River Bridge, this paper has studied the speciality of unbonded prestressed concretesimple supported small box girder.The thesis narrated the developing level and research level about the unbondedprestressed concrete structure in domestic and international. The calculate methods of ultimatestress of unbonded prestressed steel bar has been narrated. The paper introduced design dataand still load experimentation, and a set of mechanical characters such as materialnonlinear, geometric nonlinear. It indentified the method adopted in the finite elements methodnonlinear analysis which contains the relationship of the stress and the strain for material andthe solution of nonlinear equations. In light of the size of small box girder of still loadexperimentation, using ANSYS constructed the finite element model of unbonded prestressedconcrete simple supported small box girder, and simulate the process of prestressing andloading. Using the data of experimentation compared with the data of finite element model, theresult of them is adjacence. Giving a good result which is proved the finite element model isright and the way of the simulate analysis is credibility. The paper analysed the characteristic ofconcrete, bar, unbonded prestress bar and displacement farther. The finite element model ofbonded prestressed concrete simple supported small box girder has been constructed andanalysed. The paper discussed the speciality of the carrying capacity, stress of bar, and crack.