The Mechanics Performance Analysis Of Upper Structure To The Large Span Continuous Beams-Arch Combination Bridges

The Continuous Beams-Arch Combination Bridges is new-type structure of bridge,which has a good structural deformation, the train running safety, wind resistance, fatigue resistance and technical economy in combination with The large span continuous beam and arch.The Bridge has been deeply developed in the past more than ten years. One after another it has been applicated in railway bridge design. The study on design theories of Continuous Beams-Arch Combination Bridges gets relatively behind the engineering Practice.This thesis has its project background from the overpass Bridge of Xianyang West, China, the study on large span double-track railway continuous beam arch combination bridge static properties, dynamic properties, creep effect, temperature effect and other issues. The main research contents are as follows:(1) Briefly introduced the beam arch combination structure generation and long span railway bridge on the application, provided an overview of the girder and arch combination bridge stress characteristics, and describes the beam arch combination structure of the current development and research status.(2)Through the establishment of the Xianyang West overpass bridge finite element model, considering a variety of loads on the bridge in the normal state of the static behavior analysis, the results show that the deformation of structure and component stress are within permissible range.(3) The Xianyang West overpass bridge as the background, through the spatial finite element model of bridge calculated the self vibration characteristics and analysied the structural parameters on vibration characteristics effect.(4) Elaborated the significance of beam arch combination bridge creep characteristics and creep strain, the calculation method and introduced the calculation method about secondary internal force and the structure and deformation caused by the concrete creep, considering the creep on Xianyang West overpass bridge displacement.(5) Based on the finite element model of applying the temperature loads calculated beam arch combination bridge temperature effect, obtained the deflection variation of the beam arch combination bridge in different temperature load of arch rib of internal force.