武隆土坎乌江高墩大跨连续刚构桥抗震性能分析

发布时间：2018-06-22 13:48

本文选题：高墩大跨 + 连续刚构　；参考：《南华大学》2015年硕士论文

【摘要】：高墩大跨连续刚构桥具备力学性能优良、适应性强、造型幽美、跨越性强、方便施工、造价经济等诸多益处,这些优点使得我国的公路、铁路建设逐渐由平原微丘区向西南、西北山区发展。高墩大跨桥梁往往是山区交通线的重要组成部分,其地震破坏将会对整个地区的交通运输以及抗震救援工作造成巨大影响,而今,对于高墩大跨桥的抗震设计要求已超越现有规范范围,其抗震研究分析方法相对较少,且拟设计性能可能不足等,这些因素促进了高墩大跨连续刚构桥的抗震性能的分析研究,因此,了解其破坏原理和抗震能力就具有重要的现实意义。本文将对桥梁震害进行总结与梳理,并着重阐述该类桥梁震害损伤机制。以重庆市武隆县在建的土坎乌江高墩大跨连续刚构桥工程为研究对象:1.运用有限元软件ABAQUS建立该桥空间计算模型,其模型要真实反映出结构的刚度特性和质量分布情况,并对该桥的动力特性进行分析。2.获得在成桥状态下结构自振频率和振动模态及有效振型参与质量系数,探讨高墩大跨连续刚构桥在地震荷载的动力特性的变化规律,以及确立应用反应谱法对其地震作用进行振型组合时所必须的振型阶数。3.对该桥进行地震定性的分析。利用确定性方法(反应谱法和时程法)对该桥梁进行了分析,分别得到不同概率地震作用下结构的最大响应,以及分析比较两种方法的结果差异。4.考虑地震动空间变异性以及变墩高等参数对该桥地震反应特性的影响。表明:高桥墩较柔,同等条件激励下的高墩弯矩明显大于中等墩高的弯矩;高墩桥梁的墩底、墩顶剪力明显小于矮墩内力。5.依据“两水准、两阶段”设防原则,综合评估该桥的抗震性能。表明:按照现有规范设计的此桥具备很强的抗震能力,满足预期设计的要求。为该类型桥梁的抗震设计以及建设提供了参考依据,同时亦为此类桥型的抗震性能的进一步分析,提供了基石。最后,阐述了目前高架桥梁的延性抗震设计(能力保护设计)和主要构造措施在实际工程中的应用。
[Abstract]:Continuous rigid frame bridges with high piers and large spans have excellent mechanical properties, strong adaptability, beautiful shape, strong leapfrogging, convenient construction, cost and economy, and so on. These advantages have made the highway and railway construction of our country gradually move from the plain micro-hilly area to the southwest. The northwest mountain area develops. Long span bridges with high piers are often an important part of the mountain traffic line. The earthquake damage will have a great impact on the transportation and seismic rescue work in the whole region. Now, The seismic design requirements of long-span bridges with high piers have exceeded the existing specifications, and the seismic analysis methods are relatively few, and the design performance may be insufficient. These factors have promoted the seismic performance analysis of long-span continuous rigid frame bridges with high piers. Therefore, it is of great practical significance to understand its failure principle and seismic capacity. In this paper, the earthquake damage of bridges is summarized and combed, and the damage mechanism of this kind of bridges is expounded. The object of study is the construction of a large span continuous rigid frame bridge with high piers in Wulong County, Chongqing. The finite element software Abaqus is used to establish the spatial calculation model of the bridge. The model should truly reflect the stiffness characteristics and mass distribution of the structure, and the dynamic characteristics of the bridge should be analyzed. The natural vibration frequency, vibration mode and effective mode participating mass coefficient of the structure under the state of the bridge are obtained, and the variation law of the dynamic characteristics of the long-span continuous rigid frame bridge with high piers under the earthquake load is discussed. And to establish the order of mode type. 3, which is necessary for the application of the response spectrum method to the combination of the modes of the seismic action. The seismic qualitative analysis of the bridge is carried out. The deterministic method (response spectrum method and time-process method) is used to analyze the bridge. The maximum response of the bridge under different probabilistic earthquakes is obtained, and the difference between the results of the two methods is analyzed and compared. The influence of the spatial variability of ground motion and the height of pier on the seismic response of the bridge is considered. The results show that the bending moment of the high pier is obviously larger than that of the middle pier under the same conditions, and the shear force at the top of the pier of the bridge with high pier is obviously smaller than the internal force of the short pier. According to the principle of "two-level, two-stage" fortification, the seismic performance of the bridge is comprehensively evaluated. The results show that the bridge designed according to the existing code has strong seismic capacity and meets the requirements of expected design. It provides a reference for the seismic design and construction of this type of bridge, and also provides the foundation for the further analysis of the seismic performance of this type of bridge. Finally, the ductile seismic design (capacity protection design) of elevated bridges and the application of main structural measures in practical engineering are expounded.
【学位授予单位】：南华大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U442.55;U448.23

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