郑万铁路主跨128m尼尔森体系系杆拱桥动力特性与抗震性能研究

发布时间：2018-04-23 12:32

本文选题：尼尔森体系 + 动力特性　；参考：《兰州交通大学》2017年硕士论文

【摘要】：目前,针对尼尔森体系系杆拱桥动力性能方面的研究主要集中在成桥阶段,主要集中在动力特性与抗震性能方面。本文以郑万128m尼尔森体系系杆拱桥为背景,针对该桥梁施工周期长,而处于施工期的桥梁整体性不强、承载力较弱这一方面问题,具体探讨了系杆拱桥施工阶段动力特性与抗震性能。本文运用有限元软件Midas Civil建立了郑万铁路128m尼尔森体系系杆拱桥的有限元模型,运用反应谱分析方法与时程分析方法,对大桥成桥阶段的动力特性与抗震性能进行了分析,评述了该桥成桥状态的抗震性能。其次,针对该桥技术含量高、建设周期长的特点,选用下承式系杆拱桥“先梁后拱”与“先拱后梁”两种施工方法。分别进行了桥梁施工各个阶段的具体划分与建模,运用反应谱分析方法与时程分析方法对处于施工期的钢管混凝土系杆拱桥进行了地震相应分析。主要得到了以下结论:(1)本文实例系杆拱桥的振动基频为0.72Hz,对应的振型为拱肋横向对称弯曲。这表明该桥结构刚度较好。在三向震动输入的情况下,每一方向震动输入对应桥梁结构位移的主要方向。每一方向震动输入,对桥梁结构产生的内力主要作用不同。在顺桥向震动输入情况下,拱顶的最大应力值最大。在横桥向震动输入情况下,最大应力值远大于其它两个方向震动输入所引起的应力值,拱上应力由拱脚向拱顶递减,系梁应力由梁端向跨中增大。(2)对系杆拱桥按“先梁后拱”与“先拱后梁”施工方法进行了施工阶段反应谱分析与时程分析结果进行了比较分析,得到“先梁后拱”施工方法在抗震方面整体优于“先拱后梁”施工方法。
[Abstract]:At present, the research on the dynamic performance of Nielsen system tied arch bridge is mainly focused on the stage of bridge completion, mainly on the dynamic characteristics and seismic performance. In this paper, taking Zhengwan 128m Nielsen system tied arch bridge as the background, aiming at the long construction period of the bridge, but the bridge in the construction period is not strong integrity, the bearing capacity is weak. The dynamic characteristics and seismic behavior of tied arch bridge during construction are discussed in detail. In this paper, the finite element model of the 128m Nielsen system tied arch bridge of Zhengwan railway is established by using the finite element software Midas Civil. The dynamic characteristics and seismic behavior of the bridge in the stage of completion are analyzed by using the response spectrum analysis method and the time-history analysis method. The seismic behavior of the bridge is reviewed. Secondly, according to the characteristics of the bridge with high technology content and long construction period, two construction methods, "first beam and then arch" and "first arch and then beam", are selected. The concrete division and modeling of each stage of bridge construction are carried out, and the seismic analysis of concrete-filled steel tubular tied arch bridge during construction period is carried out by using the response spectrum analysis method and time-history analysis method. The main conclusions are as follows: 1) in this paper, the fundamental frequency of vibration of tied arch bridge is 0.72 Hz, and the corresponding mode is transverse symmetrical bending of arch rib. This indicates that the stiffness of the bridge is better. In the case of three direction vibration input, each direction vibration input corresponds to the main direction of bridge structure displacement. The main effect of vibration input on bridge structure is different. The maximum stress value of the arch is maximum under the condition of the vibration input along the bridge. In the case of transverse bridge vibration input, the maximum stress value is much larger than the stress value caused by the other two directions vibration input, and the stress on the arch decreases from the arch foot to the arch top. The stress of tie beam is increased from the end of beam to the middle of span. (2) the results of response spectrum analysis and time history analysis of tied-arch bridge under the construction method of "first beam and then arch" and "first arch and then beam" are compared and analyzed. It is concluded that the construction method of "first beam and then arch" is better than that of "first arch and then beam" in earthquake resistance.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U441.3;U448.225

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