考虑支座性能的高铁连续梁桥地震响应分析

发布时间：2018-01-09 07:04

本文关键词：考虑支座性能的高铁连续梁桥地震响应分析　出处：《北京交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：我国高速铁路发展过程中,桥梁所占线路里程比例较高。现行2009版《铁路工程抗震设计规范》中动力放大系数最大值βmax取值低于2015版《中国地震动参数区划图》中取值,支座损伤概率和支座性能对桥梁结构抗震性能的影响等方面工作仍有待继续深入。针对上述情况,本文依托国家自然科学基金重点项目(No.U1434210):高速铁路地震预警理论与方法研究,分析高铁连续梁桥的地震响应,研究在阻尼滞变参数与屈服指数改变下,支座性能变化对支座及桥墩地震响应的影响,验证了粘滞阻尼器的减震效果。本文的主要研究内容如下:(1)对国内外抗震规范和支座性能与桥梁地震响应的研究现状进行回顾和归纳,明确本文要研究的内容。(2)总结了高铁桥梁建模时材料的本构模型;对我国铁路抗震规范及国内其他抗震规范的设防标准进行了比较研究;对场地划分进行对比并基于场地类型选取相应地震波;建立了“六弹簧”桩—土相互作用模型。(3)以典型的40m+64m+40m三跨连续梁桥为例,针对不同轴压比和纵筋率,基于截面分析软件Xtract建立主墩墩底截面模型并进行弯矩曲率分析。基于有限元分析软件Midas/civil建立连续梁桥全桥模型,分别计算了三水准地震作用下纵、横桥向动力响应。结果表明,随着轴压比和纵筋率增加,桥墩截面屈服弯矩逐渐增大,同时延性下降;纵向墩底弯矩和横向墩顶位移在罕遇地震下接近屈服值。(4)通过改变阻尼滞变参数与屈服指数,分析支座本构关系变化对支座与桥墩地震响应的影响。研究表明,改变阻尼滞变参数对结构基于位移的屈服指标影响较大,但在支座模拟中,屈服指数往往设置为无穷大,而这对支座纵桥向抗震能力过于理想,横桥向抗震能力过于保守。组合使用不同类型支座,研究不同支座配置下墩底剪力、墩底弯矩与墩顶位移的变化规律,探究支座的最优化配置。(5)探究粘滞阻尼器对高铁连续梁桥动力响应的影响,得到针对本文结构的推荐阻尼参数,验证了粘滞阻尼器能显著提高结构抗震性能。通过连续梁桥的有限元模型数值模拟,探究了支座与桥墩响应的相关性,验证粘滞阻尼器的减震效果,为连续梁桥的服役安全以及抗震设计的发展提供了技术支撑。
[Abstract]:In the process of high-speed railway development in China. The maximum value of dynamic magnification factor 尾 max in the current edition 2009 < Code for Seismic Design of Railway Engineering > is lower than that in the 2015 edition of "China Seismic parameters Zoning Map". . The damage probability of support and the effect of bearing performance on seismic performance of bridge structure need to be further studied. Based on the research of earthquake warning theory and method of high-speed railway, the earthquake response of high-speed continuous beam bridge is analyzed by relying on the key item of National Natural Science Foundation No. No. U1434210. Under the change of damping hysteretic parameter and yield index, the effect of bearing performance change on the seismic response of bearing and pier is studied. The main contents of this paper are as follows: (1) the research status of seismic code, bearing performance and bridge seismic response at home and abroad are reviewed and summarized. (2) the constitutive model of materials used in high-speed railway bridge modeling is summarized. A comparative study is made on the fortification standards of China's railway seismic code and other domestic aseismic codes. The site division is compared and the corresponding seismic waves are selected based on the site type. A "six-spring" pile-soil interaction model is established. Taking a typical 40m 64m 40m three-span continuous beam bridge as an example, different axial compression ratios and longitudinal reinforcement ratios are considered. Based on section analysis software Xtract, the section model of main pier bottom and bending moment curvature analysis are established. Based on the finite element analysis software Midas/civil, the whole bridge model of continuous beam bridge is established. The dynamic responses of longitudinal and transverse bridges under the action of three leveling earthquakes are calculated respectively. The results show that with the increase of axial compression ratio and longitudinal reinforcement ratio, the yield moment of piers increases gradually and the ductility decreases. The bending moment of longitudinal pier bottom and the displacement of transverse pier top are close to yield value. 4) by changing damping hysteretic parameter and yield index. The influence of the change of bearing constitutive relation on the seismic response of support and pier is analyzed. The results show that the change of damping hysteretic parameters has great influence on the yield index based on displacement, but in the support simulation. The yield index is often set to infinity, which is too ideal for the seismic capacity of the longitudinal bridge and too conservative for the transverse bridge. Combined with different types of supports, the shear force at the bottom of the pier is studied with different support configurations. The influence of viscous dampers on the dynamic response of high-speed continuous beam bridges is investigated, and the recommended damping parameters for this structure are obtained. It is verified that the viscous damper can improve the seismic performance of the structure significantly. Through the finite element model numerical simulation of continuous beam bridge, the correlation between the support and the pier response is explored, and the damping effect of the viscous damper is verified. It provides technical support for the service safety of continuous beam bridge and the development of seismic design.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U442.55

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