Seismic Response Analysis Of Steel Box-Concrete Composite Bridge Structure

The steel box-concrete composite bridge structure is composed of reinforced concrete bridge deck and lower steel box girder.As the lower structure is in the form of steel box girder,which well replace the original bridge structure commonly used in the prestressed reinforced concrete box girder and can greatly reduce the weight of the structure,so as to realize the application of bridge structure in large span bridge.In recent years,the seismic performance of bridges has been a concern.Based on the existing research results,this paper discusses the seismic response of open / closed steel box-concrete composite bridge.The main contents of this paper are as follows:1)This article combined with a practical project to simplify the physical structure.And the finite element software ANSYS was used to establish the finite element model of open / closed steel box-concrete composite bridge.2)The modal analysis of the open / closed steel box-concrete composite bridge space model is carried out.The influence of the spacing of the diaphragm,the thickness of the diaphragm and the thickness of the diaphragm on the vibration characteristics of the bridge structure was discussed.And compared the vibration frequency and vibration mode of the open / closed steel box-concrete composite bridge.The results show that the steel-concrete composite bridge is a medium-flexible structure.3)The seismic response of the open / closed steel box-concrete composite bridge structure is analyzed.The seismic response of open / closed steel box-concrete composite bridge structures with different seismic waves is studied by time history analysis.At the same time,the results of structural linear and nonlinear time history analysis are compared.And compared the dynamic response of the open and closed steel box-concrete composite bridge under the same seismic wave.The results show that the torsional rigidity of the open steel box-concrete composite bridge is low.4)The self-vibration characteristics and seismic response of the structure are analyzed.It is concluded that the proper spacing of the transverse partitions can increase the Delta of the structure under the premise of satisfying the bearing capacity requirement.These conclusions will provide theoretical basis and reference for the future design and engineering application of this kind of structure.