Static And Dynamic Analysis Of A Railway Steel-concrete Composite Trussed Bridge

The steel-concrete composite truss is a new structure type which developed in recent years, and combined by triangular truss and grooved concrete slab. In the truss structure, the web member adopts steel box-concrete structure, and both the upper and bottom chords adopt concrete structure. Compared with the traditional through railway steel truss bridge, this new-type bridge has the advantages of larger stiffness, lower cost, less traffic noise, more reasonable stress and convenient construction. A 80m simply-supported steel-concrete composite trussed bridge is adopted on the Mawu-jinghe Bridge, which is located in Xian-pingliang railway line. It is the first time to adopt this type of structure on the railway bridge in our country. Taking the Mawujinghe Bridge as the engineering background, this thesis carries out the static and dynamic analysis. The main work and results include:A 3-D finite element model of the whole bridge is established by using the large finite element analysis software ANSYS. The design parameters of the bridge, including the truss height and width, panel length, and the arrangement of web members, are compared and selected for strucural optimization.The static analysis is carried out for the bridge under the design load combination. The analysis results include the vertical displacement of bridge, forces and stresses of members. Then the structural performance is further evaluated.The natural vibration analysis is carried out as well. Further more, the dynamic responses of the bridge induced by a running train is studied. Taking the CRH2 high-speed train for example, the dynamic responses of the bridge under different speed of trains is analyzed by simplifying the train vehicles as a series of concentrated forces with the actual spacing. The resonance of bridge is futher studied.