The Construction Optimization Design Of The Long-span Rigid Frame Concrete Box Arch Bridge

Factors restricting the development of bridge span are the arch material and construction technology, while rigid frame arch bridge provides a good development direction for the large-span reinforced concrete arch bridge. But the stiff skeleton of concrete arch bridge construction is a complex process, to which the choice of rigid frame and the construction plan of main arch is critical, so this article has been studied on this problem.This article took the extra large bridge-Zhaohua Jialingjiang River under construction as the background, and made a comparative analysis of the model made by large-scale finite element program model Midas Civil, and studied on the construction design.Major research work includes the following areas:①To explain the basic theory of the application of concrete-filled steel tube in arch bridge. Summarizing a reasonable calculation algorithm to cross-section's geometric characteristics of the steel tube concrete arch bridge rigid frame under different construction status, and combined the three domestic major theoretical system and specification to make a brief introduction about the mechanical properties of concrete filled steel tube.②Finite element analysis of structure. It studied on selection of unit type and main factors affecting the calculation of structure.③Research on program of rigid frame. Under the condition of certain arch section, analyzing the stress and deflection of different rigid frame program, and compared to determine the optimal solution.④Research on the perfusion order of concrete into chord pipe of rigid frame. Analyzing the effect caused by different perfusion order and age on the upper and lower chord stress, and selecting the best concrete perfusion construction sequence in pipe.⑤Research on perfusion path of the main arch. Analysis of the effect caused by different perfusion path on frame stress and arch deflection, and selecting optimal construction program of main arch, while discussion on effects on the concrete shrinkage and creep of concrete in chord pipe of rigid frame on stress and deflection of the structure.The research can provide a practical and effective solution for the construction design of extra large bridge-Zhaohua Jialingjiang River, and contribute to the rational selection of construction plan for steel tube concrete rigid frame of the main arch, and can be used as a reference for the bridge construction design of the same type.