高墩连续刚构桥车辆—桥梁冲击系数分析及改善措施

发布时间：2018-06-13 19:56

本文选题：连续刚构桥梁 + 冲击系数　；参考：《宁夏大学》2017年硕士论文

【摘要】：随着国家路网的全方位覆盖,现阶段采用、备选的公路桥梁实施方案中,尤以跨越能力突出、施工工法完善、技术工艺成熟的高墩大跨径预应力混凝土连续刚构桥梁同时具备了经济效益好和节约施工周期等优点,获得了较高频率的使用。尤其是在当前“一带一路”的战略部署下,此桥型在跨越西部高原山区有着显著的优越性,但在当前背景下,缺乏对已服役的路网核心桥梁的冲击系数及其现行影响分析研究。在项目全周期阶段,不论是设计、施工阶段还是服役阶段,冲击系数是关乎桥梁动力特性极其重要的参数。在桥梁服役阶段定期进行承载能力评估中,桥梁的动力增长效应实际上一般以冲击系数的形式显示其影响大小,据此,冲击系数研究价值凸显。本文总结了冲击系数的计算取值方式,并分别指出其相应的优点与不足;在此基础上,提出了以车辆—桥梁相互作用模型进行有限元法分析作为研究冲击系数计算方法的工具,得到桥梁结构的动力响应下的动挠度、动弯矩、竖向加速度等曲线,根据动力计算法得出在役桥梁的冲击系数。本文总结了现阶段已有的车辆—桥梁相互作用分析方法,同时多角度比较了已有方法的全过程方式方法,粗浅的提出了优点以及尚存在的纰漏。以此为基础,本文提出更优解决方案,并与已有的研究成果进行对比分析,认定此法的可行性、准确度。此后,以宁夏境内某工程实例为背景,运用上述方法,对该桥控制截面进行了与特大桥服役阶段相对应的、简化的14种工况组合分析,得到了相应的动挠度、动弯矩及其相应的冲击系数以及桥梁的竖向加速度等参数,得到了该桥各控制截面各工况下的动挠度响应及冲击系数变化规律、动弯矩响应及冲击系数变化规律、竖向加速度响应规律,并且将现行冲击系数设计规范与上述方法得到的参数相比较。通过上述研究,得到了该桥的冲击系数设计值偏于不安全,并根据得到的冲击系数变化规律提出了相应的措施,提出了采用加装液态阻尼粘滞器的措施,保证该桥服役阶段正常、平稳的运营,为国家高速公路网的运营提供有利的保障。
[Abstract]:With the comprehensive coverage of the national road network, at this stage, in the alternative highway and bridge implementation plan, especially in the case of outstanding leapfrogging capacity, the construction method is perfect. The long span prestressed concrete continuous rigid frame bridge with high piers and mature technology has the advantages of good economic benefit and saving construction cycle and has been used in higher frequency. Especially in the strategic deployment of "Belt and Road", this bridge has obvious advantages across the western plateau and mountainous areas. However, under the current background, there is a lack of analysis and research on the impact coefficient and its current impact of the core bridges in the road network. In the whole period of the project, whether in the design, construction or service stage, the impact coefficient is an extremely important parameter related to the dynamic characteristics of the bridge. In the periodic evaluation of the bearing capacity of the bridge in service stage, the dynamic growth effect of the bridge is generally shown in the form of the impact coefficient, so the research value of the impact coefficient is prominent. In this paper, the calculation method of impact coefficient is summarized, and its corresponding advantages and disadvantages are pointed out, and on this basis, the finite element analysis of vehicle-bridge interaction model is put forward as a tool to study the calculation method of impact coefficient. The dynamic deflection, bending moment and vertical acceleration of the bridge structure under dynamic response are obtained, and the impact coefficient of the existing bridge is obtained according to the dynamic calculation method. In this paper, the existing vehicle-bridge interaction analysis methods are summarized. At the same time, the full process methods of the existing methods are compared from different angles. The advantages and shortcomings of the existing methods are put forward. On this basis, this paper puts forward a better solution, and compares with the existing research results, and finds out the feasibility and accuracy of this method. Then, based on the example of a project in Ningxia, the control section of the bridge is analyzed by using the above method, which is corresponding to the service stage of the bridge, and the corresponding dynamic deflection is obtained. The dynamic bending moment and its corresponding impact coefficient, as well as the vertical acceleration of the bridge, are obtained. The dynamic deflection response and the impact coefficient change law, the dynamic moment response and the impact coefficient change law of the bridge under the different working conditions are obtained, and the dynamic bending moment response and the impact coefficient change law of the bridge are obtained. The law of vertical acceleration response is obtained, and the current design code for impact coefficient is compared with the parameters obtained by the above method. Through the above research, the design value of the impact coefficient of the bridge is found to be unsafe, and the corresponding measures are put forward according to the law of the change of the impact coefficient, and the measures of installing the liquid damping viscous device are put forward. It ensures the normal and smooth operation of the bridge, which provides favorable guarantee for the operation of the national highway network.
【学位授予单位】：宁夏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U441

【参考文献】