Studies On Mechanical Behavior Of Segmental Bridge With External Tendon And Development Of OOP

Externally prestressed bridge can be divided into two types in terms of construction method, namely monolithically erectedbuilt bridge and precast segmental one. The application of external prestressing technology combined with precast segmental building method is becoming more and more popular throughout engineering field due to its incomparable advantages. For precast segmental concrete bridges with external prestressing, on the one hand, the deformation and hence the stress in the external tendon is member dependent rather than section dependent, on the other hand, the joints only works in the state of compression. All above characteristics make it much sophisticated to make a mechanical analysis.In the base of character analysis on precast segmental concrete bridges with external prestressing, considering the advantages of widely application and high calculation precision, the separate type model is picked out after an overview of existing concrete Finite Element (FE) model (including separate type model, composite type model and integral type model), which is mainly at the aim of accurately simulating its mechanical characteristic. The paper presents the joint model of the same displacement constraint, which enriches and develops the FE approaches of simulating joint. Combined with nonlinearity theory, geometry nonlinearity and material nonlinearity is deduced, as well as FE formulation of joint element. Then a FE numerical model is established which is capable of performing structural analysis of precast segmental concrete bridges with external prestressingA detailed development is presented which devotes to discuss how to realize Object-Orient Program (OOP) in FE field. Then a FE model is programmed with Visual Studio.NET, which takes into account geometric nonlinearity as well as material nonlinearity and can analyze segmental bridge from origin up to failure.With the experimental model and the program, the paper implements a parameter analysis which devotes to discuss some factors having influences on the structural behaviour of precast segmental concrete bridges with external prestressing. The factors include the number of joint, ratio of shear span to effective depth, initial stress in external tendon and area of steel bar in top flange.