Study On Isolation Of High Damping Rubber Bearing In Curve Beam Bridge

Curved beam bridge has a good adaptability to space restriction due to the advantage of smooth linetype.Because of its spatial structure characteristics,the state of stress of curved girder bridge is more complicated,and it is vulnerable under the seismic excitation.In this thesis,the seismic response and the seismic mitigation of curved beam bridge are analyzed in depth.The main research is as follows:Taking a curved girder bridge as research object,the analysis model is established based on midas software.Time history analysis method is used to compare structural seismic response before and after isolation,the isolation effect of high damping rubber(HDR)bearing is analyzed The difference of structural seismic response and isolation effect under different seismic waves are compared,the parameters of different HDR bearing type is analyzed.By changing the height of pier,the influence of pier height on structural seismic response and HDR isolation effect is discussed.By changing the radius of curvature from 200 meters to infinity,the influence of radius of curvature on structural seismic response and HDR isolation effect is also discussed.EI seismic waves of different angles are input to the structure,the most unfavorable seismic wave input direction of internal force and displacement of curved beam bridge with HDR bearing are discussed.Some conclusions have been drawn from above work:compared to the structure before isolation,the self-vibration period of the structure with HDR bearing is increased.The basic structural period is more than two times that of non-seismic isolation.Structural response before and after isolation is obviously different,with the isolation device,the internal force of pier bottom and the displacement of pier top have been largely reduced,the basic damping rate is about 30%to50%,fixed pier damping rate is higher.With the increase of pier height,the self-vibration period of the model before and after isolation are both on the rise.HDR bearing keeps good shock absorption effect under different pier high model,the radial damping rate is higher than the tangential damping rate.Compared with the pier height,the change of the radius of curvature has little effect on the vibration period of the structure.When the radius of curvature changes from 200 meter to infinity,the structure exhibits different damping rates at different radius of curvature,but are basically keeped in stable range.Under the excitation of one-dimensional seismic wave,the most unfavorable input direction of structure internal force and displacement is relatively clear.Under the excitation of two-dimensional seismic wave,the most unfavorable input direction of structural internal force is closely related to the selection of seismic wave.