铁路连续梁桥一般只设一个固定墩,并由其承担上部结构的全部地震纵向荷载,这极易造成固定墩和伸缩缝破坏,甚至造成引桥落梁.基于连续梁桥活动墩的抗震潜能,提出在各活动墩与梁体之间设置锁死销连接装置.地震时,活动墩和固定墩协同受力,提高连续梁桥的整体抗震性能.以某典型铁路连续梁桥为例,研究锁死销的减震原理及对活动墩的影响,分析跨度、跨数以及温差对锁死销减震效果的影响.研究表明:在地震作用下锁死销可有效降低固定墩的内力响应和梁端纵向位移响应,明显提高连续梁桥的整体抗震性能;对于常规铁路连续梁桥,锁死销的减震效果受温差的影响较小,可以按年平均温度进行设置.%A railway continuous bridge is generally provided with one fixed pier,which bears all the longitudinal seismic load of the superstructure,which is likely to result in damage to the fixed pier or the expansion joint and even lead to falling-beam damage of the approach bridge.To this end,aseismic thought of continuous beam bridge based on the aseismic potential of the sliding piers was put forward and an acceleration activating locking dowel was installed between the sliding piers and the continuous girder.The sliding piers can bear the longitudinal seismic force of the superstructure cooperating with the fixed pier once the earthquake occurs,improving the overall aseismic performance of continuous bridge.Meanwhile,a typical project of a railway continuous bridge was taken as an example to illustrate the earthquake reduction principle of the locking dowel and the influence of the locking dowel on the sliding piers.The effect of span,the number of spans and the temperature difference on the earthquake reduction effect of the locking dowel was analyzed.According to the research results,the locking dowel can significantly reduce the seismic response on the fixed pier and longitudinal displacement response of beam-end,and thus improve the overall aseismic performance of continuous bridge.Besides,for conventional railway continuous bridge,as the earthquake reduction effect of the locking dowel was less affected by the change of environment temperature,the locking dowel can be set according to the annual average temperature.
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