刘家峡悬索桥地震反应分析及减震措施研究
发布时间：2018-10-10 18:46
【摘要】：近些年来，随着我国在基础设施建设方面的快速发展，所修建的桥梁结构的数量大幅增加，桥梁结构形式也因为美观上的要求多种多样，而悬索桥这种古老的桥型，却始终焕发着旺盛的生命力。 地震作用下，桥梁结构经常遭到破坏，给人们的通行以及救灾造成很大的不便，所以对结构进行地震反应分析，并根据分析结果采取抗震或者减隔震措施显得非常必要。 本文以刘家峡悬索桥为工程背景，利用有限元分析软件MIDAS/CIVIL建立全桥模型，分析其动力特性，计算其地震反应，并根据地震反应结果采取减震措施并对减震效果进行评价和对比。具体主要工作内容如下： （1）查阅文献，对在地震荷载作用下桥梁结构遭到的破坏形式进行分析，发现在结构的破坏过程中，支座往往最先遭到破坏，作为连接桥梁上、下部结构的重要部分，它的破坏会造成上部结构的滑移、脱落以及倾覆，上部结构的脱落和倾覆又会造成下部结构的破坏。 （2）利用有限元分析软件MIDAS/CIVIL建立了刘家峡悬索桥的动力分析有限元模型，在建立基础模型的过程中，考虑到桩基与土的相互作用，本文利用弹性地基梁法，模拟桩—土效应。建立整体模型后，对其进行自振特性分析，为后面的地震反应分析做准备。 （3）根据桥址区地质条件以及抗震要求，确定要输入到桥梁结构中的反应谱函数，然后对模型进行反应谱分析，分析过程中考虑结构在不同输入方向下的地震反应。 （4）根据场地周期以及地质条件等，确定三组不同的经典地震波作为输入到结构中的地震荷载，对这三组波进行调整，使其符合拟建场地的要求，然后求解结构在该三组波作用下的地震反应，并对其进行分析。 （5）根据地震反应结果，本文决定给结构添加液体粘滞阻尼器作为减震措施。根据文献和资料，确定适合结构的粘滞阻尼器，，对其阻尼系数、阻尼指数等技术参数进行分析。并将这些参数输入到桥梁结构的有限元模型中。 （6）给结构添加粘滞阻尼器后，对其进行地震反应分析，得出结构在添加减震措施后，结构的内力值和位移值，并将该值与未添加减震措施时的结构地震反应值进行对比。 （7）经对比可知，结构在添加减震措施后，结构在塔顶处以及梁端支座处的顺桥向和横桥向的地震位移幅值明显降低，塔底的内力值也明显减小，说明该减震措施效果较好。
[Abstract]:In recent years, with the rapid development of infrastructure construction in our country, the number of bridge structures built has increased significantly, and the form of bridge structure is also varied because of aesthetic requirements, and suspension bridge is an ancient bridge type. But always radiant with exuberant vitality. Under earthquake action, bridge structure is often damaged, causing great inconvenience to people's passage and disaster relief, so it is very necessary to analyze the seismic response of the structure and to take seismic or seismic isolation measures according to the analysis results. Taking the Liujiaxia suspension bridge as the engineering background, the finite element analysis software MIDAS/CIVIL is used to establish the full bridge model, to analyze its dynamic characteristics, to calculate its seismic response, and to take measures to reduce the earthquake according to the results of the seismic response, and to evaluate and compare the seismic absorption effect. The main contents of the work are as follows: (1) referring to the literature and analyzing the damage form of bridge structure under earthquake load, it is found that in the process of structural damage, the support is often first destroyed. As an important part of the connecting bridge and the substructure, its failure will cause the superstructure to slip, fall off and overturn. The shedding and overturning of the superstructure will cause damage to the substructure. (2) the finite element model of the Liujiaxia suspension bridge is established by using the finite element analysis software MIDAS/CIVIL. Considering the interaction between pile foundation and soil, this paper simulates the pile-soil effect by means of elastic foundation beam method. After the whole model is established, the natural vibration characteristics of the model are analyzed to prepare for the subsequent seismic response analysis. (3) according to the geological conditions of the bridge site and the seismic requirements, the response spectrum function to be input into the bridge structure is determined. Then the response spectrum of the model is analyzed, and the seismic response of the structure in different input directions is considered. (4) according to the site period and geological conditions, Three sets of different classical seismic waves are determined as the seismic load input to the structure, and the three sets of waves are adjusted to meet the requirements of the proposed site, and then the seismic response of the structure under the action of the three sets of waves is solved. (5) according to the results of seismic response, this paper decides to add liquid viscous damper to the structure as a shock absorption measure. According to the literature and data, the viscous damper suitable for the structure is determined, and the technical parameters such as damping coefficient and damping index are analyzed. These parameters are input into the finite element model of bridge structure. (6) after adding viscous damper to the structure, the seismic response of the structure is analyzed, and the internal force and displacement value of the structure after adding the damping measures are obtained. This value is compared with the seismic response value of the structure without adding the damping measures. (7) by comparison, the structure after adding the damping measures, The amplitude of seismic displacement and the internal force at the bottom of the tower are obviously reduced at the top of the tower and at the support of the beam end, which indicates that the effect of the measure is good.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.25
本文编号：2262853
[Abstract]:In recent years, with the rapid development of infrastructure construction in our country, the number of bridge structures built has increased significantly, and the form of bridge structure is also varied because of aesthetic requirements, and suspension bridge is an ancient bridge type. But always radiant with exuberant vitality. Under earthquake action, bridge structure is often damaged, causing great inconvenience to people's passage and disaster relief, so it is very necessary to analyze the seismic response of the structure and to take seismic or seismic isolation measures according to the analysis results. Taking the Liujiaxia suspension bridge as the engineering background, the finite element analysis software MIDAS/CIVIL is used to establish the full bridge model, to analyze its dynamic characteristics, to calculate its seismic response, and to take measures to reduce the earthquake according to the results of the seismic response, and to evaluate and compare the seismic absorption effect. The main contents of the work are as follows: (1) referring to the literature and analyzing the damage form of bridge structure under earthquake load, it is found that in the process of structural damage, the support is often first destroyed. As an important part of the connecting bridge and the substructure, its failure will cause the superstructure to slip, fall off and overturn. The shedding and overturning of the superstructure will cause damage to the substructure. (2) the finite element model of the Liujiaxia suspension bridge is established by using the finite element analysis software MIDAS/CIVIL. Considering the interaction between pile foundation and soil, this paper simulates the pile-soil effect by means of elastic foundation beam method. After the whole model is established, the natural vibration characteristics of the model are analyzed to prepare for the subsequent seismic response analysis. (3) according to the geological conditions of the bridge site and the seismic requirements, the response spectrum function to be input into the bridge structure is determined. Then the response spectrum of the model is analyzed, and the seismic response of the structure in different input directions is considered. (4) according to the site period and geological conditions, Three sets of different classical seismic waves are determined as the seismic load input to the structure, and the three sets of waves are adjusted to meet the requirements of the proposed site, and then the seismic response of the structure under the action of the three sets of waves is solved. (5) according to the results of seismic response, this paper decides to add liquid viscous damper to the structure as a shock absorption measure. According to the literature and data, the viscous damper suitable for the structure is determined, and the technical parameters such as damping coefficient and damping index are analyzed. These parameters are input into the finite element model of bridge structure. (6) after adding viscous damper to the structure, the seismic response of the structure is analyzed, and the internal force and displacement value of the structure after adding the damping measures are obtained. This value is compared with the seismic response value of the structure without adding the damping measures. (7) by comparison, the structure after adding the damping measures, The amplitude of seismic displacement and the internal force at the bottom of the tower are obviously reduced at the top of the tower and at the support of the beam end, which indicates that the effect of the measure is good.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.25
【参考文献】
相关期刊论文 前1条
1 周云,邓雪松,黄文虎;耗能减震结构的抗震设计原则与设计方法[J];世界地震工程;1998年04期
本文编号：2262853
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