利用摩擦摆支座对既有桥梁隔震加固的研究

发布时间：2018-03-31 05:11

本文选题：Midas　切入点：civil　出处：《西安科技大学》2015年硕士论文

【摘要】：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的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。
[Abstract]:At present, there are a large number of existing bridges in our country with insufficient seismic capacity, which is mainly due to the fact that the design of existing bridges is based on the idea of single leveling fortification based on strength, and the elastic design method is relatively backward. In addition, our country is located on a number of seismic plates. Frequent earthquakes seriously threaten the lives and property of the people. As lifeline projects, bridges play an important role in the earthquake relief process. It is necessary to strengthen the existing bridges with insufficient seismic performance. The research content of this paper is based on the friction pendulum isolation bearings, which are widely used in foreign countries. This paper analyzes the application effect of this method in the isolation and strengthening of existing bridges. Taking a three-span continuous beam bridge located in a class I site as an example, The 3D dynamic analysis model of the bridge is established by using the finite element analysis software Midas civil. The modal analysis shows that the bridge is rigid as a whole, and the horizontal mode mass is mainly concentrated in the first two modes, which is suitable for strengthening with the seismic isolation scheme. The seismic behavior of the continuous beam bridge is analyzed by Push-over method, and the seismic performance of the continuous beam bridge is evaluated according to the rules of 08. Therefore, it is necessary to strengthen the bridge against earthquake. Then, the friction pendulum isolation support is designed for the bridge. After replacing all the supports of the original bridge for modal analysis, the basic period of the bridge strengthened by isolation is extended to more than 3 times of the original bridge. The results show that the effect of the internal force at the bottom of the bridge pier decreases significantly under the action of the E _ 1 / E _ 2 leveling earthquake, respectively. At the same time, a linear damping device is installed to control the displacement of the superstructure of the bridge. It is proved that the friction pendulum isolation support and linear damping device are effective in isolation and reinforcement of three-span continuous beam bridges. Finally, in order to compare the different isolation and reinforcement effects of bridges with different piers, the original bridge model is taken as the benchmark. By adjusting the height of the pier to 5m and 20m, it is found that the isolation effect of the bridge with low pier is better than that of the bridge with low pier.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.72

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