独斜塔斜拉桥地震响应分析及减隔震支座研究

发布时间：2018-06-09 01:43

本文选题：独斜塔斜拉桥 + 反应谱　；参考：《兰州交通大学》2014年硕士论文

【摘要】：二十几年来，随着国内经济的飞速增长，城市建设也得到快速发展，同时大量人口聚集到城市，人们对城市交通的依赖性也越来越强，要求也越来越高。独斜塔斜拉桥作为一种近年来出现的新型桥梁结构，因为其结构合理性，充分的利用和发挥不同材料的各自特性，加上其造型优美，越来越得到业内的广泛关注，将来势必成为城市桥梁的重要选择之一。但因为该桥型结构出现相对较晚，目前其实际应用仍然较少，且对其抗震性能以及减隔震措施的研究更是少之又少，尤其是减隔震措施方面。同时近些年国内连续发生了几次大地震，一再展示了桥梁工程遭到破坏后带来的后果，因而对独斜塔斜拉桥的抗震分析与减隔震措施方面的研究就显得更为迫切与需要，同时也可为同类桥梁的减隔震设计提供借鉴与参考，具有重要的实际意义。本文以某城市公路独斜塔斜拉桥为工程背景，通过采用有限元计算软件Midas/Civil建立全桥的空间有限元模型，对大桥进行结构动力特性分析以及地震动响应分析，并在前面分析的基础上对大桥原设计采用的抗震型支座进行抗震验算，作出效果评价。主要研究工作及内容如下： (1)建立某城市公路独斜塔斜拉桥空间有限元模型，在考虑桩土效应与刚性地基两种情况下，采用Midas/Civil软件对其进行自振特性计算，并对比分析结果。 (2)根据规范正确设计反应谱以及合理的选择实录地震波，分别按反应谱分析法与动力时程分析法对大桥结构进行偶遇地震条件下的地震动响应分析，并比对两种方法的计算结果，得出采用动力时程分析法对大桥结构进行地震动响应分析更偏于安全，同时为后面进行减隔震支座的减震效果分析研究提供数据支持。 (3)对原设计采用的两种减隔震支座，即对抗震型盆式橡胶支座、抗震型球形钢支座进行模拟，这里使用Midas/Civil中的滞后系统。通过对比大桥结构在加入减隔震支座前后的内力与变形，以验证随着这两种抗震支座的加入，桥塔与主塔墩的受力情况是否得到改善以及减隔震的效果如何。 (4)通过比对采取减隔震措施前后的大桥结构的地震动响应，得出：由于桥塔与主塔墩承受了绝对部分荷载，其余各边墩及辅助墩分担的荷载很小，因此，即使两种抗震支座在一些程度上减小了边墩及辅助墩的内力，但是对于大桥整体结构的抗震能力而言几乎没有影响，，作为主要承力部分的桥塔及主塔墩的内力基本没有变化。因此，想通过在边墩及辅助墩设置抗震型支座以增大上部结构动能来耗散地震能量行不通。
[Abstract]:Over the past 20 years, with the rapid growth of the domestic economy, urban construction has also developed rapidly. At the same time, a large number of people have gathered in cities, and people have become more and more dependent on urban transportation. Single inclined tower cable-stayed bridge as a new type of bridge structure in recent years, because its structure is reasonable, make full use of and play the respective characteristics of different materials, and its shape is beautiful, More and more wide attention in the industry, the future is bound to become an important choice of urban bridges. However, due to the relatively late emergence of the bridge structure, its practical application is still relatively small, and the research on its seismic performance and isolation measures is even less, especially in the aspect of seismic isolation measures. At the same time, in recent years, there have been several large earthquakes in China, which have repeatedly demonstrated the consequences of the damage of bridge engineering, so the research on seismic analysis and isolation measures of single inclined tower cable-stayed bridge becomes more urgent and necessary. At the same time, it can also provide reference and reference for the design of isolation and isolation of similar bridges, which is of great practical significance. This paper takes the single inclined tower cable-stayed bridge of a city highway as the engineering background. By using the finite element calculation software Midas / Civil to establish the spatial finite element model of the whole bridge, the dynamic characteristics of the bridge and the ground motion response are analyzed. On the basis of the previous analysis, the aseismic bearing of the original design of the bridge is checked and calculated, and the effect is evaluated. The main research work and contents are as follows: (1) the spatial finite element model of a single inclined tower cable-stayed bridge on a city highway is established. Considering the pile-soil effect and rigid foundation, the natural vibration characteristics of the bridge are calculated by Midas / Civil software. According to the correct design of the response spectrum and the reasonable selection of the recorded seismic waves, the seismic response of the bridge structure under the accidental earthquake is analyzed according to the response spectrum analysis method and the dynamic time-history analysis method, respectively. Compared with the calculation results of the two methods, it is concluded that the dynamic time-history analysis method is more safe for the seismic response analysis of the bridge structure. At the same time, it provides data support for the analysis and study of the effect of seismic isolation support. 3) the two kinds of shock isolation bearings used in the original design, that is, the earthquake resistant basin rubber bearing and the seismic spherical steel bearing, are simulated. The hysteresis system in Midas / Civil is used here. By comparing the internal force and deformation of the bridge structure before and after adding the shock isolation support, it is verified that with the addition of these two kinds of seismic support, By comparing the seismic response of the bridge structure before and after adopting the isolation measures, it is concluded that the bridge tower and the main tower pier bear absolute partial load. The rest of the side piers and auxiliary piers share very little load, so even though the internal forces of the side piers and auxiliary piers are reduced to some extent by the two kinds of seismic supports, they have little effect on the seismic capacity of the whole structure of the bridge. As the main bearing part, the internal force of the bridge tower and the main tower pier is basically unchanged. Therefore, it is not feasible to dissipate seismic energy by installing seismic bearing in side pier and auxiliary pier to increase the kinetic energy of superstructure.
【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】：U442.55;U448.27

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