Study On Vibration Control Viscous Damper In Simply Supported Continuous Box Girder Bridge

Prestressed concrete simple-supported to continuous box girder bridge has been widely used in bridge engineering across roads and rivers because of its simple structure and clear stress characteristics.Under the action of seismic load,the bridge structure and components will be damaged accordingly,so it is particularly important to study the seismic performance of continuous girder bridges.In this paper,the finite element analysis model of the structure of the simply supported continuous box girder bridge in Tangtong Highway with 4×30+3×30m is established.The three-dimensional spatial non-linear seismic time history analysis of the bridge model is carried out by choosing Tianjin seismic wave and Anderson seismic wave with peak acceleration of 0.3g as two waveforms with different spectrum characteristics,including the non-linear seismic response analysis of the continuous girder bridge.The influence of additional viscous dampers on seismic response of bridges is analyzed from three aspects: displacement of pier top,bending moment of pier bottom and shear force of support.The parameters of different viscous dampers are optimized and analyzed,and the optimal parameters and reasonable layout form suitable for this type of bridge are designed.The main contents of the analysis include the following points: firstly,the mechanical model of viscous damper and its shock absorption mechanism are analyzed;secondly,the finite element model is established,and the modal analysis is carried out.Through the time history response analysis of the structure under three-dimensional seismic excitation,the influence of different seismic parameters on the seismic response of the bridge is analyzed;finally,the influence of viscous damper on the structure of the bridge is compared and analyzed,and the bridge structure is determined.The first order vibration frequency and mode of beam structure along the bridge are calculated,and then the parameters of viscous dampers(such as damping coefficient and velocity index)are determined.The expected effect of structural vibration reduction can be achieved by reasonable design and arrangement of dampers.