针对我国高速铁路CRTSⅡ型板式无砟轨道桥梁的结构特点，以京沪高铁某段10跨简支梁为实际工程背景，同时考虑轨道约束及后继路基段的影响，采用反应谱法研究了地震作用下无砟轨道系统关键构件参数取值以及墩高变化对桥梁结构地震反应的影响。研究结果表明：端刺能很大程度上传递地震荷载，其刚度越大路基段分配的荷载越大，桥墩的地震反应减小；剪力齿槽是传递纵向荷载的重要结构，在地震中若刚度下降，将会降低轨道系统向端刺结构传递荷载的能力；轨道约束系统对非规则桥梁的地震反应影响较大，墩高相差越大，影响越显著。高墩墩底弯矩大幅降低，矮墩墩底弯矩明显增大。%In view of structural characteristics of CRTS Ⅱ slab ballastless track bridges of high-speed railway in China,a section of 10-span simply supported bridge of Beijing-Shanghai High-speed Railway is taken as the practical engineering background to study the influence of the dif-ferent values of key parameters,such as end thrust stiffness,shear alveolar stiffness and pier height on the pier internal force and pier top displacement of the bridge under earthquake by using response spectrum method with consideration of the influence of track restraint and subsequent embankment.The result shows that the end thrust can transfer the earthquake load greatly,and the larger the end piercing stiffness is,the greater the seismic load distribution is,which can also reduce the seismic response of the pier.The shear alveolar is the important structure for transfer-ring the longitudinal load,and the decrease of its stiffness will lead to the decrease of the ability of the track system to transfer the load to the end thrust structure.The track restraint system has great effect on the seismic response of the irregular bridge,and the more difference between the height of piers is,the more obvious the influence is.Furthermore,the moment decreases greatly at the bottom of the higher pier,while it increases significantly at the bottom of the lower pier.
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