高速铁路混凝土重力式桥墩抗震验算方法研究

发布时间：2018-03-07 22:02

本文选题：铁路　切入点：多遇地震　出处：《兰州交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：我国高速铁路(客运专线)上广泛采用低配筋混凝土重力式桥墩。由于对配筋率在0.5%以下的混凝土重力式桥墩的抗震设计方法缺乏研究,现行的《铁路工程抗震设计规范》对此类桥墩的抗震验算方法没有做出规定。本文通过模型试验与理论分析相结合的方法对少筋混凝土重力式桥墩的抗震性能及验算方法进行研究,主要研究工作如下： (1)在阅读大量文献资料基础上,分析了混凝土桥墩的震害特点,分析了少筋混凝土桥墩抗震性能研究现状并指出了目前抗震设计中存在的问题。 (2)以高速铁路桥梁常用跨度少筋混凝土重力式桥墩为研究对象,通过1：8桥墩模型拟静力试验得到了少筋混凝土桥墩在不同配筋率下(0.10%～0.5%)的墩身破坏特征、裂缝分布、承载能力及滞回特性,分析了配筋率对耗能能力的影响。 (3)研究了多遇地震作用下少筋混凝土重力式桥墩验算指标的合理限值。通过计算墩底截面弯矩-曲率分析了少量主筋对墩身强度及抗倾覆稳定性的作用。计算了由稳定性及强度分别控制抗震设计时反算的截面容许偏心,通过比较,建议采用容许应力法验算墩身强度时反算的容许偏心限值。 (4)基于模型试验结果,给出了少筋混凝土重力式桥墩位移延性建议值。建立了有限延性的非线性时程分析模型,提出了罕遇地震作用下少筋混凝土重力式桥墩基于有限延性的抗震设计方法。并对一具体工程进行了算例分析,验证了分析方法的可行性。 (5)提出了基于有限延性的弹性地震力折减方法及罕遇地震作用下少筋混凝土重力式桥墩的简化分析方法,给出了具体的分析过程。应用该简化分析方法,通过大量的数值分析,统计得到了不同地震烈度区高速铁路32m跨度双线简支梁桥墩的合理配筋率建议值。
[Abstract]:Low reinforced concrete gravity piers are widely used in high speed railway (passenger dedicated lines) in China. Due to the lack of research on seismic design methods of concrete gravity piers with reinforcement ratio below 0.5%, The current Code for Seismic Design of Railway Engineering does not provide for the seismic checking method of this kind of pier. In this paper, the aseismic performance of gravity pier with less reinforcement concrete and the seismic behavior of gravity pier with less reinforcement are studied by combining model test with theoretical analysis. Check the calculation method to carry on the research, The main work of the study is as follows:. 1) on the basis of reading a large number of documents, this paper analyzes the characteristics of earthquake damage of concrete pier, analyzes the present situation of seismic performance of concrete pier with less reinforcement and points out the existing problems in seismic design. (2) taking the concrete gravity piers with little reinforcement commonly used in high speed railway bridges as the research object, the failure characteristics and crack distribution of the pier are obtained by pseudostatic test of 1: 8 pier model under different reinforcement ratios (0. 10% and 0. 5%). The influence of reinforcement ratio on energy dissipation capacity is analyzed. This paper studies the reasonable limit value of checking calculation index of gravity bridge pier with less reinforcement under the action of frequent earthquake. By calculating the bending moment-curvature of section of pier bottom, the effect of small amount of main reinforcement on the strength of pier body and stability against overturning is analyzed. The eccentricity of the inverse section in seismic design is controlled by stability and strength respectively. By comparison, it is suggested that the allowable eccentricity limit should be calculated by the allowable stress method when the strength of the pier body is checked. 4) based on the model test results, the suggested displacement ductility of gravity piers with less reinforcement is given, and a nonlinear time-history analysis model with finite ductility is established. A seismic design method based on finite ductility for gravity pier of concrete with few reinforcement subjected to rare earthquake is proposed. An example is given to verify the feasibility of the method. In this paper, an elastic seismic force reduction method based on finite ductility and a simplified analysis method for gravity pier of concrete with little reinforcement under rare earthquake are proposed, and the concrete analysis process is given. Using this simplified analysis method, a large number of numerical analyses are carried out. The rational reinforcement ratio of 32 m span simple supported beam piers of high speed railway in different seismic intensity regions is obtained statistically.
【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

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