Analysis Of Dynamic Characteristics Of Concrete Filled Steel Tubular Arch Bridges And Seismic Response

Concrete filled steel tube arch bridge appears to inject new vitality into the development of arch bridge. With the high bearing capacity, strong spanning ability, good seismic behavior and convenience of construction, concrete filled steel tubular arch bridges develop in the direction of large-span and lightweight style. A lot of problems will be consequent on the increase of the span, the weight of the structure of loss. The dynamic behavior of concrete filled steel tubular arch bridge is highlighted particularly, such as seismic resistance, wind resistance, the impact of the vehicle load vibration. The article based on the arch bridge dynamics principles and methods, the space finite element calculation modes set up by the finite element method, calculates the dynamic behavior of through concrete filled steel tubular arch bridge, as follows:1. With simple space of curved, neglecting the effects of shear deformation and warping, the Hamilton principle was used to derive plane of vibration equation of elastic spatial arch and the nonlinear dynamic equations of elastic spatial arch under three-displacement-freedom and one-rotation-freedom. The article simplified the equations and set up circular arch in-plane vibration equations. It also laid the foundation for the further study of linear or nonlinear dynamic behavior of spatial arch.2. In view of the limitations of solving ability of analytic method theory, the article has to solve dynamic equations by numerical analysis method. In current science and technology development and engineering analysis, the finite element method is to obtain the most widely used numerical method, as a result of its universal and effectiveness. Engineering and technology highly attach importance to the method. This article expounded the structural dynamic finite element method of the arch bridge and the solving method, which provided theoretical basis for the next step in the vibration characteristics and dynamic response analysis of concrete filled steel tube arch bridge, but also holp to the analysis result of qualitative judgment, avoid making mistakes.3. Taking the example of Urumqi River tied arch bridge, the3-D finite element model was ste up and the natural vibration characteristics was calculated with the FEM software Midas Civil. The structure of crossbars, type of suspender, wide-span ratio, and steel ratio on dynamic characteristics were compared and analyzed. The article got the quantitative influence law.4. Applying the current seismic resistance theory, selecting and entering the adjusted EL-Centro wave, San Fernando wave, Tianjinl wave, the seismic behavior which was in two of the standard(P1.P2probability level) and three-way bridge (longitudinal、horizontal and vertical) was analyzed by transient analysis method, together with it to provide relevant reference for considering affect design of seismic design of the similar bridge.