Study On The Influence Of Cracking On The Deflection Of Thin-walled Concrete Box Girders

The cracking phenomena of Thin-walled concrete box girder bridge is considered tobe “the cancer of concrete box girder”. The crack developments, not only affects the safetyand durability of the structure, but also exacerbates the deflection. Therefore, the theoreticalstudy of the relationship between the crack and deflection of the concrete thin-walledbox girder, exploring the related law, has important theoretical significance and engineeringapplication value. This paper mainly completed the following aspects of the work:（1）Reviewed the research progress and development status at home and abroad onthe deflection calculation of box girder, Based on the relevant research of concretethin-walled box girder crack phenomenon, put forward the main content in this paper.（2） Considering material nonlinearity of reinforced concrete box beam, using FEAsoftware ANSYS, Based on the Drucker-Prage five parameters failure criterion and randomreinforcement model, established the finite element simply supported reinforced concretebox girder model.（3） Step loading on the box girder model until the crack get the forecast width. Studythe development situation, distribution of box girder model of normal section cracksand diagonal cracks, and reinforced under different load levels of stress and deflection change.Comparing the above results with the corresponding box beam test shows that Both valuescoincide well. Verified that using this paper’s finite element model of the thin-walledconcrete box girder cracking effect on the deflection is feasible.（4）Based on previous literature, quantitative analysis factors that the Influence on thedeflection, such as, bending deformation、shear lag effects、shear deformation and so on.Considering the influence of the development of the inclined section cracks on sheardeformation, based on variable angle truss model, In the process of analysis deflection causedby shear deformation increases,...