大跨连续刚构桥箱梁抗震分析与减震措施研究

高烈度地震区大跨连续刚构桥箱梁在地震作用下会发生弯曲变形,产生较大弯矩和剪力,对箱梁抗裂及承载能力产生不利影响。为减小连续刚构桥箱梁在地震作用下的内力,以(90+190+228+123+60)m刚构+连续梁协作体系桥为例,采用有限元软件Midas Civil建模,对主墩墩型和支座类型的影响进行抗震分析并提出减震措施。研究结果表明:①主墩采用双薄壁墩比独柱式空心薄壁墩对箱梁抗震有利;②在辅助墩、交界墩或桥台处设置高阻尼隔震橡胶支座,可以减小箱梁和主墩受力;③在主桥梁端纵桥向设置粘滞阻尼器可以显著降低箱梁和主墩的弯矩;④组合使用高阻尼隔震橡胶支座+粘滞阻尼器减震措施,可以在不中断交通的情况下显著提升连续刚构桥的抗震性能。

The Research on Seismic Absorption Measures and Seismic Analysis About the Box Girder on Large-span Continuous Rigid Frame Bridge

The bending deflections will occur at box girder on Large-span Continuous Rigid Frame Bridge in earthquake intensity when earthquake occur,which will bring about great bending moment and shearing force.Such results will bring advert impacts on box girder crack resistance and carrying capacity.In order to reduce the internal force on box girder when earthquake occur,the 90+190+228+123+60 meters continuous rigid frame bridge&continuous beam cooperative system bridge is used to study.The effect of the main pier type and the supporting system were researched in seismic analysis.Some shock absorption measures were presented.Some research results were indicated.The double thin-wall piers are beneficial to box girder earthquake resistance than single thin-wall piers.The measures that high damping rubber bearings were installed on auxiliary piers,juncture piers or abutments are effective to reduce the seismic force of box girder and main piers.The viscous dampers which were installed among box girder and abutments along longitudinal are prominently effective to reduce the seismic bending moments of box girder and main piers.The combination measures that high damping rubber bearings and viscous dampers are used together can be greatly effective to promote the earthquake resistance performance of continuous rigid frame bridge under situation of no traffic disruption.