刚构—连续梁组合体系桥梁力学特性及地震响应分析

发布时间：2018-03-22 22:19

本文选题：桥梁工程　切入点：刚构桥-连续梁组合体系桥梁　出处：《长安大学》2014年硕士论文　论文类型：学位论文

【摘要】：预应力混凝土（PC）刚构-连续梁组合体系桥梁综合了连续刚构桥和连续梁桥的优点，在力学性能、使用功能和地形适应性方面具有一定的优越性，特别适合西部山区地质和地形条件，是跨越复杂地质条件、深沟、陡坡路段的首选桥型之一。为进一步推广和应用此类新型桥梁结，需要详细掌握此类新型桥梁结构的力学特性和地震响应特点，因此开展预应力混凝土刚构-连续梁组合体系桥梁的力学特性分析和地震响应方面的研究具有重要的工程应用价值和美好前景。本文以某库区对外交通桥为工程实例，开展预应力混凝土刚构-连续梁组合体系桥梁的力学特性和地震响应分析方面的研究工作，研究的主要内容有：（1）运用Midas/civil有限元软件建立了某库区对外交通桥的有限元计算模型，并结合桥梁的实际材料特性、边界条件和以往同类桥梁建模的注意事项对有限元计算模型进行适当的修正，并根据交通桥设计的施工图纸进行施工阶段的划分和模拟，为后续结构力学特性分析和地震响应分析奠定坚实的基础。（2）运用建立的精细有限元模型进行库区交通桥结构静力力学特性和结构动力特性的计算分析，主要研究在承载能力极限状态不同荷载组合下桥梁结构的安全性能；进行正常使用极限状态不同荷载组合下结构正截面抗裂验算、斜截面抗裂验算和结构刚度验算；进行持久状况结构应力的验算，考虑了不同荷载组合下结构的正截面法向应力的验算和斜截面法向应力的验算；针对库区交通桥的施工阶段分析和现行桥梁设计规范，给出库区交通桥的施工预拱度设置与分配情况；采用适合求解大型特征值问题的lanczos法进行库区交通桥自由振动特性的分析，为后续库区交通桥地震响应分析奠定基础。（3）在总结已有关于地震响应研究成果的基础上，，运用反应谱分析法和动力时程分析法进行库区交通桥的地震响应分析，反应谱法考虑两种地震E1地震和E2地震两种情况，动力时程分析法以典型强震记录波EL-Centro为基础并根据库区交通桥的实际情况进行适当调整；根据计算结果研究在不同荷载组合下桥墩和主梁的内力和位移变化情况，以了解库区交通桥的地震响应特点，并进行应谱分析法和动力时程分析法计算结果的比较分析，校核与验证两种计算方法的计算结果的正确性，确保为结构的抗震设计提供相对可靠的计算依据。
[Abstract]:Prestressed concrete (PC) rigid frame-continuous beam composite system bridge integrates the advantages of continuous rigid frame bridge and continuous beam bridge, and has some advantages in mechanical performance, use function and terrain adaptability. It is especially suitable for geological and topographic conditions in western mountainous areas, and is one of the preferred bridge types for crossing complex geological conditions, deep ditches and steep slope sections. It is necessary to master the mechanical characteristics and seismic response characteristics of this new type of bridge structure in detail. Therefore, the analysis of mechanical characteristics and seismic response of prestressed concrete rigid frame-continuous beam composite bridge has important engineering application value and bright prospect. Taking an external traffic bridge in a reservoir area as an engineering example, this paper studies the mechanical characteristics and seismic response of prestressed concrete rigid frame-continuous beam composite bridge. The main contents of the study are as follows:. 1) the finite element calculation model of an external traffic bridge in a reservoir area is established by using Midas/civil finite element software. Combining with the actual material characteristics of the bridge, the boundary conditions and the matters needing attention in the modeling of the same bridge in the past, the finite element calculation model is modified appropriately. According to the construction drawing of the traffic bridge design, the construction stage is divided and simulated, which lays a solid foundation for the subsequent structural mechanical characteristics analysis and seismic response analysis. 2) the fine finite element model is used to calculate and analyze the static and dynamic characteristics of the traffic bridge structure in the reservoir area, and the safety performance of the bridge structure under different load combinations under the limit state of bearing capacity is mainly studied. The crack resistance of normal section, the crack resistance of oblique section and the stiffness of structure under different load combinations under normal service limit state are calculated, and the structural stress of the lasting condition is checked. The normal stress of normal section and normal stress of inclined section under different load combinations are considered, and the analysis of construction stage of traffic bridge in reservoir area and the current design code of bridge are discussed. The construction pre-arch setting and distribution of traffic bridges in the reservoir area are given, and the lanczos method suitable for solving large eigenvalue problems is used to analyze the free vibration characteristics of the traffic bridges in the reservoir area, which lays a foundation for the seismic response analysis of the traffic bridges in the subsequent reservoir area. 3) on the basis of summarizing the existing research results on seismic response, the response spectrum analysis and dynamic time-history analysis are used to analyze the seismic response of traffic bridges in the reservoir area. The response spectrum method considers two kinds of earthquakes, E1 earthquake and E2 earthquake. The dynamic time-history analysis method is based on the typical strong earthquake recording wave EL-Centro and is adjusted appropriately according to the actual situation of the traffic bridge in the reservoir area. According to the calculation results, the variation of the internal force and displacement of the pier and the main beam under different load combinations are studied. In order to understand the characteristics of seismic response of traffic bridges in the reservoir area, and to compare and analyze the calculated results of the corresponding spectrum analysis method and the dynamic time history analysis method, the correctness of the calculation results of the two calculation methods is checked and verified. To ensure that the seismic design of the structure to provide a relatively reliable basis for calculation.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U442.55

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