Thin-walled Box Girders Of Reinforced Concrete Nonlinear Force Performance Analysis

In order to find out its nonlinear behaviors deeply, the theoretical research and parametric study on reinforced concrete thin-walled box-girder has been presented in this thesis based on the nonlinear finite element theory.First of all, the application and development of reinforced concrete box girder in the civil engineering are reviewed, and the state-of-the art about its nonlinear research at home and abroad has been summed up. Sequentially, primary research content and purpose of the thesis are put forward.Secondly, with the help of a new type of plate and shell element and the layered model to simulate the reinforced concrete nonlinear process under loading, a nonlinear finite element procedure has been developed. And the results obtained from the program shows a good agreement with those from the test, which demonstrates that the methods and program developed in this thesis are feasible and practical. The full range analysis from cracking to crashing of box girder are conducted in detail to ascertain the response for the structure to load, and the parametric study about the shear lag of box girder within the nonlinear stage has been finished and some profitable conclusions have been obtained as well.Thirdly, in this thesis, the influence of concrete creep to the behaviors especially to the nonlinear behaviors of reinforced-concrete box girder has also been studied and the effect of creep on internal force, deformation, ultimate load capacity and shear lag of reinforced concrete box-girder has been included, and the parameter such as loading duration, age of concrete and sustained load are considered.Finally, the primary results and corresponding conclusions have been listed. Some improvement and advices to the design of reinforced concrete box girders are brought forward.