大跨度斜拉桥地震激励的动力响应与减震设计分析

发布时间：2018-11-29 10:57

【摘要】：在交通运输工程中,大跨度桥梁起着关键性作用,其投资较大,对国民经济的发展有较大影响。如果在地震作用下桥梁遭到破坏,将会给经济带来较大的损失,另一方面也会影响到灾区的救灾和重建工作。正因为如此,如何提高斜拉桥抗震减震能力就列为重要的科研方向。当地震发生时,为了使大跨度斜拉桥有足够的安全性,必须采取积极有效的抗震减震措施,提高相应的经济和社会意义。当对大跨度斜拉桥进行抗震减震设计时,其设计思想为:斜拉桥在地震作用下,位移和内力越小对结构越有利,但一般情况下这两者不能同时满足,比如位移越小必然以较大内力为代价。本文以淮安大桥为研究背景,使用大型桥梁通用软件建立了三个不同的模型,分别为采用粘滞阻尼器的斜拉桥模型、采用水平拉索减震的斜拉桥模型以及没有采取任何减震措施的斜拉桥模型,并分别对这三种模型进行了自振特性分析。通过时程分析,得到阻尼器和弹性拉索的减震效果和合理设计参数(阻尼器的合理阻尼系数和弹性拉索的合理弹性刚度)。分析得出,不论是采用弹性拉索减震还是粘滞阻尼器减震,只要参数合理,都可以很好的控制结构的位移,也会减小结构的内力响应。综合分析两种减震方案,得出在斜拉桥上设置粘滞阻尼器才是最佳的减震方案。该方案不仅符合减震设计的规范要求,而且也提高了斜拉桥材料的耐久性以及结构在减震方面的能力。可供其他桥梁做减震分析和设计的参考。
[Abstract]:In the transportation engineering, the long-span bridge plays a key role, and its investment is large, which has great influence on the development of the national economy. If the bridge is damaged by the earthquake, it will bring great losses to the economy, on the other hand, it will also affect the disaster relief and reconstruction work. Therefore, how to improve the seismic capacity of cable-stayed bridges is an important research direction. In order to make the long-span cable-stayed bridge safe enough when the earthquake occurs it is necessary to take active and effective anti-seismic measures to improve the corresponding economic and social significance. When the long-span cable-stayed bridge is designed for seismic shock absorption, the design idea is as follows: the smaller the displacement and the internal force of the cable-stayed bridge under the earthquake, the more favorable the structure is, but generally the two can not be satisfied at the same time. For example, the smaller the displacement, the greater the internal force. Taking Huai'an Bridge as the research background, three different models of cable-stayed bridge with viscous dampers are established by using the general software of large-scale bridges. The model of cable-stayed bridge with horizontal cable damping and the model of cable-stayed bridge without any damping measures are used, and the natural vibration characteristics of these three models are analyzed respectively. Through time history analysis, the damping effect and reasonable design parameters of dampers and elastic cables are obtained (the reasonable damping coefficient of dampers and the reasonable elastic stiffness of elastic cables). It is concluded that the displacement of the structure can be controlled well and the internal force response of the structure can be reduced by using elastic cable or viscous damper as long as the parameters are reasonable. By synthetically analyzing two kinds of shock absorption schemes, it is concluded that viscous dampers on cable-stayed bridges are the best ones. This scheme not only meets the requirements of the design specifications, but also improves the durability of the cable-stayed bridge material and the ability of the structure to reduce the earthquake. It can be used as a reference for the analysis and design of other bridges.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U442.55;U448.27

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