高墩大跨PC连续刚构桥动力分析与荷载试验研究

发布时间：2018-03-01 21:06

本文关键词： 连续刚构桥有限元动力分析荷载试验　出处：《重庆交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：预应力混凝土（PC）连续刚构桥以其线形优美、受力合理、施工方便、跨越能力大等诸多优点在我国桥梁建设过程中得到广泛应用，在桥梁结构建成通车之前需要对结构受力性能进行全面的检测评定，荷载试验作为检测桥梁性能的最常用试验方法之一发挥着重要作用。本文首先回顾了连续刚构桥的发展历程及受力特点，并系统阐述了桥梁结构试验检测的相关知识。以西苏角特大桥为依托工程，从工程实际出发建立三维空间有限元模型，并结合静载试验对桥梁在车道荷载作用下内力进行分析；结合依托工程在边跨布置永久压重混凝土的工程实际，分析了压重混凝土对桥梁整体线形的影响，提出了对设计压重集度适当增大范围的建议。根据结构动力特性计算理论，采用子空间迭代法求解动力方程特征值及特征向量，计算出结构的自振模态；以依托工程的结构振型和频率，详细分析了高墩大跨连续刚构桥的各项动力特性，为今后此类桥梁的设计、施工以及运营管养提供参考；采用MIDAS/Civil移动荷载时程分析模块，自定义车辆移动荷载时程函数，对不同车速下结构的动力响应进行分析，提取了不同车速下桥梁中跨跨中节点的位移时程数据，分析得出了车速与连续刚构桥的动力系数之间的变化规律。简要介绍了桥梁结构荷载试验的相关理论；结合相关理论及有限元分析结果，制定试验方案，包括试验桥跨、控制截面、加载工况及车辆布载等，，按照试验方案实施加载并对相关数据进行采集，通过与计算值对比得出校验系数，利用校验系数结合规范对桥梁的实际承载能力进行评价。采用车辆荷载对桥跨进行跑车、刹车、跳车试验以及脉动试验，对结构动力特性及动力响应进行测试，与通过有限元模型得出的结构竖向振型和频率进行对比，判定桥梁结构的动力特性是否正常，同时根据动载试验实测数据计算出结构的冲击系数和阻尼比等参数。
[Abstract]:Prestressed concrete continuous rigid frame bridge has been widely used in the process of bridge construction in our country with its advantages of graceful alignment, reasonable force, convenient construction and large span capacity. Before the bridge structure is completed and opened to traffic, it is necessary to carry out a comprehensive test and evaluation of the structure's mechanical performance. Load test plays an important role as one of the most commonly used test methods to test the bridge's performance. In this paper, the development history and stress characteristics of continuous rigid frame bridge are reviewed, and the related knowledge of bridge structure test and detection is expounded systematically. Based on the project of the large bridge in the west of Suzhou corner, a three-dimensional finite element model is established from the engineering practice. Combined with the static load test to analyze the internal force of the bridge under the action of driveway load, combined with the engineering practice of placing permanent compression concrete in the side span, the influence of the compression concrete on the overall alignment of the bridge is analyzed. The suggestion of increasing the range of design weight set is put forward. According to the theory of structural dynamic characteristic calculation, the eigenvalue and eigenvector of the dynamic equation are solved by subspace iteration method, and the natural vibration modes of the structure are calculated based on the structural mode and frequency of the engineering. The dynamic characteristics of long-span continuous rigid frame bridge with high piers are analyzed in detail, which provides a reference for the design, construction and operation of this kind of bridge in the future. The MIDAS/Civil moving load time history analysis module is used to define the vehicle moving load time history function. The dynamic response of the structure under different speeds is analyzed, and the displacement time history data of the mid-span node of the bridge under different speeds are extracted, and the variation law between the velocity and the dynamic coefficient of the continuous rigid frame bridge is obtained. This paper briefly introduces the relevant theory of the bridge structure load test, combines the relevant theory and the finite element analysis result, formulates the test plan, including the test bridge span, the control section, the loading condition and the vehicle distribution load, etc. According to the test scheme loading and collecting the relevant data the check coefficient is obtained by comparing with the calculated value and the actual bearing capacity of the bridge is evaluated by the check coefficient combined with the code. The vehicle load is used to test the dynamic characteristics and dynamic response of the bridge span by means of sports car, brake, jump test and pulsation test, which is compared with the vertical mode and frequency obtained by the finite element model. Whether the dynamic characteristics of bridge structure is normal or not, the parameters such as impact coefficient and damping ratio are calculated according to the measured data of dynamic load test.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.23;U441

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