地震作用下城市轻轨连续刚构桥的动力效应分析

发布时间：2018-06-18 20:21

本文选题：地震作用 + 城市轻轨　；参考：《重庆交通大学》2014年硕士论文

【摘要】：城镇化进程的蓬勃发展带来了城市交通系统的日益拥挤,相应给城市居民出行及生活造成困难。跨座式轻轨可以极大地缓解交通压力，而且对起伏复杂的地形有较强的适应能力，有效的缓解了目前城市交通与城市发展的矛盾。以重庆嘉陵江轻轨专用连续刚构桥为工程背景，利用桥梁分析软件Midas Civil建立有限元模型，做了以下几个方面的研究工作： ①论述地震灾害的特点以及国内外近年来发生的较大地震实况；分析地震波的特性及其地震波与桥梁结构的空间相关性；研究跨座式单轨交通系统的发展历程以及目前国内外的发展状况。 ②构建地震介质传导作用下轻轨列车通过连续刚构桥的动力特性新理念，从地震波介质载体动态演化特征入手，研究地震波不同介质对桥梁结构内力的影响，探寻其动态传递规律，得到不同地震波介质和不同场地条件下桥梁结构响应。 ③通过多重Ritz向量法对连续刚构桥的自振特性分析，计算得到结构的前十阶自振频率、周期和振型，并分析各个振型的特性；定义轻轨列车荷载、编组方式和各种工况，分析各种工况条件下连续刚构桥和轨道梁各个控制截面的位移、加速度响应以及各项动力指标所反映的桥梁实际状况；得出位移幅值主要集中在8～17s，加速度幅值主要集中在中间时段的结论。 ④提出地震作用下列车-轨道-连续刚构桥空间动力分析模型，分析在地震作用下列车过桥时的动力作用机理；采用多点激励形式的动态时程分析方法，选取Elcent地震波，分析连续刚构桥在行车和地震作用双重荷载下的动力和内力时程响应，得出主跨跨中是薄弱部位，最大位移为8.2cm，最大加速度为2.07m/s2；承受轴力最大的部位是桥墩结构，最大值为6763.09KN，主梁的最大轴力和弯矩在主跨的跨中处，为2602.40KN和26982.32kN·m，是整座桥的薄弱部位。 ⑤对地震作用下城市轻轨通过连续刚构桥时桥梁结构以及运行车辆本身的安全性做深入的研究，确保乘车人的生命和财产安全。从不同桥墩高度，不同行车速度以及不同地震波强度三个方面，对所建的模型进行地震作用下的响应分析，，提出在地震发生时列车安全运营的建议。
[Abstract]:With the rapid development of urbanization, urban traffic system is becoming more and more crowded, which makes it difficult for urban residents to travel and live. The straddle light rail can greatly relieve the traffic pressure, and has a strong adaptability to the complex terrain, which effectively alleviates the contradiction between urban traffic and urban development. Taking the special continuous rigid frame bridge of Jialing River Light Rail in Chongqing as the engineering background, the finite element model is established by using the bridge analysis software Midas Civil. The research works are as follows: (1) the characteristics of earthquake disaster and the large earthquakes occurring at home and abroad in recent years are discussed, and the characteristics of seismic wave and the spatial correlation between seismic wave and bridge structure are analyzed. This paper studies the development course of straddle monorail transportation system and the current development situation at home and abroad. (2) constructing a new concept of dynamic characteristics of light rail train passing through continuous rigid frame bridge under seismic medium conduction, Based on the dynamic evolution characteristics of seismic wave medium carrier, the influence of different seismic wave media on the internal force of bridge structure is studied, and the dynamic transfer law of seismic wave medium carrier is explored. The responses of bridge structures under different seismic wave media and different sites are obtained. 3 the natural vibration characteristics of continuous rigid frame bridges are analyzed by multiple Ritz vector method, and the first ten natural frequencies, periods and modes of the structure are calculated. It also analyzes the characteristics of each mode, defines the load, marshalling mode and various working conditions of the light rail train, and analyzes the displacement of each control section of the continuous rigid frame bridge and track beam under various working conditions. Acceleration response and the actual state of the bridge reflected by each dynamic index; It is concluded that the displacement amplitude is mainly concentrated in 8 ~ 17s, and the acceleration amplitude is mainly concentrated in the middle period. 4 the spatial dynamic analysis model of train-track continuous rigid frame bridge under earthquake action is put forward. The dynamic mechanism of train crossing bridge under earthquake action is analyzed, and the dynamic and internal force response of continuous rigid frame bridge under the dual loads of driving and earthquake is analyzed by using the dynamic time-history analysis method of multi-point excitation form and selecting Elcent seismic wave. The maximum displacement is 8.2 cm, the maximum acceleration is 2.07 m / s ~ 2, the maximum axial force is the pier structure, the maximum value is 6763.09 KN, and the maximum axial force and bending moment of the main beam are at the middle of the main span, the maximum displacement of the main span is 8.2 cm and the maximum acceleration is 2.07 m / s ~ (2), and the maximum axial force is 6763.09 KN. For 2602.40KN and 26982.32kN, it is the weak part of the whole bridge. 5 the safety of the bridge structure and the running vehicle itself when the urban light rail passes through the continuous rigid frame bridge under earthquake is studied deeply to ensure the life and property safety of the passenger. From three aspects of different piers height, different driving speed and different seismic wave intensity, the response analysis of the model under earthquake action is carried out, and some suggestions for safe operation of trains in the event of earthquake are put forward.
【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;U441.3

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