当前我国有大量既有桥梁存在抗震能力不足的情况，其原因主要是既有桥梁设计时基于强度的单一水准设防理念、弹性设计方法比较落后。加之我国处于多个地震板块之上，频发地震严重威胁着人民的生命和财产安全，而桥梁作为生命线工程，在抗震救灾过程发挥很大作用，鉴于此，对抗震性能不足的既有桥梁进行抗震加固很有必要。 本文研究内容基于目前在国外使用较广的摩擦摆隔震支座，分析其在既有桥梁减隔震加固当中的应用效果。以某位于Ⅰ类场地的三跨连续梁桥为例，利用有限元分析软件Midas civil建立该桥三维动力分析模型。经模态分析表明该桥梁整体刚性较大，水平方向振型质量主要集中于前两阶模态，适合应用减隔震方案进行加固；进一步应用Push-over方法对该连续梁桥进行抗震性能分析，根据08细则评价其抗震性能不满足要求，因此需要对其进行抗震加固。 之后为该桥设计摩擦摆隔震支座，更换原桥所有支座进行模态分析，隔震加固后的桥梁基本周期延长至原桥3倍以上。分别在E1、E2两水准地震作用下分析其减隔震效果，发现桥梁墩底内力效应大幅下降，满足了规范要求。同时针对桥梁上部结构的位移过大问题设置线性阻尼装置，使得其位移也得到控制，证明摩擦摆隔震支座与线性阻尼装置配套使用在该三跨连续梁桥的隔震加固中效果显著。最后为对比不同墩高的桥梁隔震加固效果的不同，以原桥模型为基准，调整墩高为5m以及20m，经分析发现低墩桥梁隔震效果相对更好。

At present, due to the concept of a single level of defence based on intensity and flexible design method of the existing bridge fallen behind relatively, China has a large number of bridges which are under the situation of lacking seismic resistance. Coupled with the idea of China continent is over a plurality of seismic sections, frequent earthquakes have a huge threat to security on people's lives and property, and the bridges which are known as the lifeline of the project play a significant role in the process of disaster relief. In view of these, seismic reinforcement for existing bridges which are lack of the seismic performance is very necessary. Research in this paper is based on the friction pendulum support which is widely uesd in foreign countries currently , and it will analyze FPS’ isolation effect on the seismic reinforcement of existing bridge. This paper takes a three-span continuous girder bridge which is located in theⅠclass site for example, use the finite element analysis software Midas civil to build three-dimensional dynamic model of the bridge. Eigenvalue analysis shows that the bridge has high overall rigidity and its modal quality focus on the first and the second modal in horizontal direction, so the seismic reinforcement of this bridge is suitable for isolation solution. Then it use Push-over method to analyze this continuous beam bridge, according to the “08 rules” to evaluate the seismic performance of the bridge and turns out that it does not meet the requirements, so it needs to be seismic reinforced. Then it designs FPS for the bridge to replace all the original supports of the bridge and takes eigenvalue analysis, the result shows that the new bridge’s natural vibration period extended to more than three times of the original bridge. Then it analyzes the seismic effect of isolation in E1 and E2 two-level earthquake, finds that effects of internal forces of the bridge piers dropped significantly and meet the regulatory requirements; meanwhile, considering for the displacement of the bridge superstructure is too large, it sets viscous damping device so that the displacement can also be controlled. Then it proves that using FPS with linear damping devices together to reinforce the three-span continuous girder bridge has remarkable effect. Finally, this paper takes the original bridge model as a bench mark, adjusting the pier height to 5m and 20m, in this way, to compare and analysis the different effect of isolation reinforcement with different height. It founds that the isolation effect of low pier bridge is relatively better.