考虑车辆作用的曲线梁桥地震动力响应特性研究

发布时间：2019-03-03 17:30

【摘要】：由于地震发生难以预测,当桥梁遭遇地震时桥上存在运营车辆的情况较为常见。当车辆过桥时,由于车桥耦合关系,车桥系统下的地震响应与单独桥梁的地震响应会存在一定的差异性。与直线梁桥相比,曲线梁桥的弯扭耦合效应与空间动力特性使得车辆作用对桥梁地震响应的影响变得更加复杂。现行公路与城市桥梁抗震设计规范中,尚无关于曲线梁桥抗震设计中是否考虑车辆作用的相关规定。开展考虑车辆作用下的曲线梁桥地震动力响应特性研究,对于该类桥型的抗震设计与分析具有重要的理论意义与实用价值。为此,本文以曲线梁桥为对象,开展了考虑车辆动力作用及其关键参数影响的该类桥梁地震动力行为特性研究。获得的主要研究结果如下:首先,利用模态综合法建立了曲线梁桥的车桥耦合动力方程,基于MATLAB编写了适用于曲线梁桥的车桥动力分析程序。以一座曲线高墩钢管混凝土桁架梁桥为例,利用该桥的现场试验结果,对所编写的分析程序进行了验证。利用该程序,系统分析了车速、路面平整度、车辆数和车辆行驶位置等参数对该桥例的整体和局部冲击效应及行车舒适性的影响。结果表明现行规范大幅低估了该桥的车辆冲击效应,其局部构件的冲击系数因位置不同差异较大;此外,该桥行车舒适性相对较差。然后,给出了人工地震波的生成方法,基于模态综合法建立车辆-地震-桥梁相互作用动力分析方程,并编写了相应的地震-车-桥动力分析程序。以一座四跨混凝土曲线连续箱梁桥为例,基于该桥缩尺模型地震振动台试验结果,对所建立的方法和动力分析程序进行了间接验证。结果表明所建立的车-地震-桥梁动力分析方法和程序具有较高的分析精度和适用性,可用于后继的考虑车辆作用下的桥梁地震动力响应分析研究。最后,以一座四跨混凝土曲线连续箱梁桥为例,利用所编写的动力分析程序,分析了不同地震波及输入角度条件下,车辆作用对桥梁地震动力响应的影响,并系统研究了车重、车速、地震动峰值、场地条件和桥墩墩高等关键参数变化时,车辆作用对曲线梁桥地震动力反应的影响特点和规律。研究结果表明:车辆作用对曲线梁桥地震反应的影响显著,抗震分析中应考虑车辆作用的不利影响;考虑车辆作用的不利影响时,应将地震沿边墩连线和边墩垂线方向输入;随着车重和车速的提高,车辆作用对桥梁地震响应的影响呈增大趋势。此外,随地震动峰值提高,车辆作用的不利影响幅度会降低;特定场地条件下,车辆作用可产生对桥梁地震反应有利的响应,且地震波频率分布集中时,车辆作用的影响较大;车辆作用对桥梁地震响应的影响与桥墩高度的变化无明显相关性,规律较为复杂。
[Abstract]:Because the earthquake is difficult to predict, when the bridge is hit by the earthquake, it is more common to have running vehicles on the bridge. When the vehicle crosses the bridge, there will be some difference between the seismic response of the vehicle-bridge system and that of the single bridge due to the coupling relationship between the vehicle-bridge system and the single bridge. Compared with the linear beam bridge, the bending-torsional coupling effect and the spatial dynamic characteristics of the curved beam bridge make the influence of the vehicle action on the seismic response of the bridge more complicated. In the current code for seismic design of highway and urban bridges, there is no relevant regulation on whether the action of vehicles should be taken into account in the seismic design of curved girder bridges. It is of great theoretical significance and practical value for the seismic design and analysis of curved beam bridges to carry out the research on the seismic response characteristics of curved girder bridges under the action of vehicles. Therefore, taking curved beam bridge as an object, the seismic dynamic behavior of this kind of bridge considering the dynamic action of vehicle and its key parameters is studied in this paper. The main research results are as follows: firstly, the vehicle-bridge coupling dynamic equation of curved beam bridge is established by means of modal synthesis method, and the dynamic analysis program for curved beam bridge is compiled based on MATLAB. Taking a curved high-pier concrete-filled steel tube truss girder bridge as an example, the analysis program is verified by using the field test results of the bridge. By using the program, the effects of vehicle speed, pavement smoothness, vehicle number and vehicle driving position on the overall and local impact effects and driving comfort of the bridge are systematically analyzed. The results show that the current code greatly underestimates the vehicle impact effect of the bridge, and the impact coefficient of the local components varies greatly due to the location of the bridge. In addition, the driving comfort of the bridge is relatively poor. Then, the generation method of artificial seismic wave is given. Based on the modal synthesis method, the dynamic analysis equation of vehicle-earthquake-bridge interaction is established, and the corresponding seismic-vehicle-bridge dynamic analysis program is compiled. Taking a four-span concrete curved continuous box girder bridge as an example, based on the seismic shaking table test results of the scale model of the bridge, the established method and dynamic analysis program are indirectly verified. The results show that the established method and program for vehicle-earthquake-bridge dynamic analysis are of high accuracy and applicability, and can be used to analyze the dynamic response of bridges under the action of vehicles. Finally, taking a four-span concrete curved continuous box girder bridge as an example, the influence of vehicle action on the seismic response of a four-span concrete continuous box girder bridge under different earthquake and input angles is analyzed by using the dynamic analysis program, and the vehicle weight is systematically studied. When the speed, the peak value of ground motion, the site conditions and the high key parameters of piers and piers are changed, the characteristics and rules of the influence of vehicle action on the seismic dynamic response of curved beam bridges are studied. The results show that the influence of vehicle on the seismic response of curved beam bridge is obvious, and the adverse effect of vehicle should be considered in seismic analysis, and when the adverse effect of vehicle action is considered, the earthquake should be inputted along the line of side pier and the vertical line of side pier. With the increase of vehicle weight and speed, the influence of vehicle action on the seismic response of bridges tends to increase. In addition, with the increase of the peak value of earthquake ground motion, the adverse effect amplitude of vehicle action will decrease, and the vehicle action can produce favorable response to the bridge seismic response under the condition of specific site, and the influence of vehicle action is greater when the frequency distribution of seismic wave is concentrated. There is no obvious correlation between the influence of vehicle action on the seismic response of bridge and the change of pier height, and the rule is more complicated.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U442.55

【参考文献】