行波激励下多跨连续隔震桥梁的地震反应分析

发布时间：2018-07-09 11:18

本文选题：多跨连续隔震桥梁 + 铅芯橡胶隔震支座　；参考：《广州大学》2014年硕士论文

【摘要】：地震是复杂的空间运动，在对平面尺寸较大的结构进行地震反应分析的时候地，应该考虑地震动的空间变化。对于多跨连续隔震桥梁而言，由于其本身自带隔震装置的特殊性，在行波效应对多跨连续隔震桥影响方面的研究成果相对较少。基于此背景，本文的主要研究对象为一座六跨连续隔震桥梁，在其基础上进行行波效应研究分析。本文主要从以下几个方面展开相关研究，并根据分析所得总结出了相应的结论： 1、对采用铅芯橡胶隔震支座的隔震桥梁进行水平简谐行波作用下的结构响应机理研究。本文主要从研究输入地震动卓越周期对隔震桥梁结构响应的影响进行分析。为模拟具有不同主频率的地震动，采用具有不同频率特性的正弦波对隔震桥梁进行一直激励及多点行波激励来实现，分析结果表明：行波效应对隔震桥梁各部分的影响有所不同，当激励频率小于结构自振周期时，行波效应对下部结构会出现不利的情况，，对隔震层不利性明显；当激励频率大于结构自振频率时，行波效应对隔震桥梁都是有利的；而对于桥梁的上部结构，任何时候行波效应对其都是有利的。 2、采用三条地震波对铅芯隔震桥梁进行行波激励下的地震反应分析，结果表明：桥梁的地震响应会因不同地震波的频谱成分的差异性以及同一地震波不同波速激励下而表现出很大的差异。一般来说，长周期频谱成分越重，地震视波速越小对隔震桥梁的响应也就越不利。 3、对隔震桥梁进行单向、双向以及三向行波输入，结果表明：单维或多维行波激励下，隔震桥梁的响应并无明显差异，多向激励下纵桥向行波效应反应规律可参照单向输入。行波效应对横桥向响应的影响很小，基本可以忽略。 4、通过振动台试验来验证隔震技术的有效性以及观测两点行波激励对隔震桥梁的影响，并对试验模型进行有限元模拟仿真分析，验证振动台试验以及主要结论的可靠性。
[Abstract]:Earthquake is a complex spatial movement. The spatial variation of ground motion should be taken into account in seismic response analysis of structures with large plane size. For multi-span continuous isolation bridge, due to the particularity of its own isolation device, there are few research results on the effect of traveling wave effect on multi-span continuous isolation bridge. Based on this background, the main research object of this paper is a six span continuous isolation bridge, on the basis of which the traveling wave effect is studied and analyzed. This article mainly from the following several aspects to carry out the related research, The conclusions are summarized as follows: 1. The structure response mechanism of the isolated bridge with lead-rubber isolation bearing under the action of horizontal harmonic traveling wave is studied. In this paper, the effect of the excellent period of input ground motion on the response of isolated bridge structure is studied. In order to simulate the ground motion with different main frequencies, sine waves with different frequency characteristics are used to carry out the continuous excitation and the multi-point traveling wave excitation to the isolated bridge. The results show that the traveling wave effect has different effects on each part of the isolated bridge. When the excitation frequency is less than the natural vibration period of the structure, the traveling wave effect will be disadvantageous to the substructure, and the disadvantage to the isolation layer will be obvious. When the excitation frequency is greater than the natural vibration frequency of the structure, the traveling wave effect is beneficial to the isolated bridge, while for the superstructure of the bridge, the traveling wave effect is beneficial to the isolated bridge. The traveling wave effect is beneficial to the bridge at any time. 2. Using three seismic waves to analyze the seismic response of lead-core isolated bridge under traveling wave excitation, The results show that the seismic response of the bridge will be greatly different due to the difference of the spectral components of different seismic waves and the excitation of the same seismic wave with different velocities. Generally speaking, the heavier the long-period spectrum is, the less the apparent velocity of seismic waves is, and the less the seismic velocity is, the less the seismic response of isolated bridges is. 3. The one-way, bidirectional and three-way traveling-wave inputs are carried out on the isolated bridges. The results show that there is no significant difference in response of isolated bridges under single or multidimensional traveling wave excitation, and the response law of longitudinal traveling wave effect can be referred to unidirectional input under multi-direction excitation. The traveling wave effect has little effect on the transverse bridge response and can be neglected. 4. The vibration table test is used to verify the effectiveness of the isolation technique and to observe the effect of the two-point traveling wave excitation on the seismic isolation bridge. The finite element simulation analysis of the test model is carried out to verify the reliability of the shaking table test and the main conclusions.
【学位授予单位】：广州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U442.55

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