桥墩防车辆撞击研究

发布时间：2018-01-06 22:11

本文关键词：桥墩防车辆撞击研究　出处：《湖南大学》2015年博士论文　论文类型：学位论文

【摘要】：多起国内外撞击事故表明,当遭遇大型车辆的撞击时,按现有规范设计的桥墩可能发生断裂破坏并引起桥梁整体垮塌,从而造成更为严重的二次灾害,并导致整条公路长时间封闭等严重后果。因此,对车辆撞击桥墩问题进行研究具有重要的现实意义;而如何对桥墩进行合理有效的防撞设计已成为目前亟待解决的问题。本文首先对相关文献进行了综述分析,包括钢筋混凝土梁柱构件抗侧向冲击性能研究、车辆撞击桥墩防护结构的研究、车辆撞击桥墩等柱类结构物的研究以及中、美、英等国相关设计规范等。分析表明,目前桥墩防车辆撞击研究尚处于起步阶段,许多关键问题还没有解决。例如车辆撞击柱类结构物的撞击机理、车辆撞击力计算方法以及桥墩防车辆撞击设计的指导原则等。本文大量采用非线性有限元分析对卡车与桥墩的撞击规律进行了研究。在卡车与刚性及弹性桥墩的撞击分析中,重点考察卡车的撞击行为以及撞击力时程曲线等撞击结果。针对桥墩截面尺寸和形状、卡车撞击速度、卡车质量、路面坡度、卡车货物刚度以及卡车与桥墩之间的偏心距离等一系列参数对撞击效应的影响进行了仔细研究。在卡车与弹塑性钢筋混凝土桥墩的有限元分析中,重点探讨剪切破坏控制下钢筋混凝土构件的有限元仿真模拟方法以及桥墩上、下部结构对撞击效应的影响等,旨在为钢筋混凝土桥墩的防撞设计提供参考。本文提出将卡车与桥墩撞击简化为具有三个自由度的耦合质量-弹簧-阻尼模型,即CMSD模型;其中卡车首次被简化为并联双自由度质量-弹簧-阻尼模型,桥墩则简化为单自由度质量-弹簧-阻尼模型。该CMSD模型可以对卡车撞击桥墩问题进行时程分析,从而得到卡车撞击力、桥墩反力、桥墩特征点位移甚至是卡车挤压变形量等关键信息。基于CMSD模型进行了一系列参数分析,得到了卡车质量、撞击速度及桥墩截面特征等与撞击力或桥墩支座反力之间的关系曲线。对考虑卡车撞击特征的单自由度模型、双自由度模型以及CMSD模型分别进行了反应谱分析。结果表明,CMSD模型反应谱与双自由度模型反应谱相似。本文最终基于双自由度模型反应谱拟合得到了卡车撞击桥墩弹性设计反应谱,从而奠定了桥墩防车辆撞击设计的基础。另外,考虑到实车碰撞试验成本高昂,本文提出了一种价格廉价的等效卡车钢架试验模型,用于代替大型卡车对柱类结构物进行撞击试验研究。该模型内部结构非常简单,仅由若干槽型钢及钢块制成,但它考虑了参考卡车的实际几何和物理特征。通过与精细卡车有限元模型进行对比分析,验证了该等效卡车钢架模型具有与实际卡车相似的撞击特性。本研究还首次采用缩尺(1/3)等效卡车钢架模型对钢筋混凝土柱进行了落锤冲击试验,对钢筋混凝土柱和等效卡车钢架模型的破坏形态等进行了研究。总之,本文采用有限元分析、编程以及试验研究等多种方法对车辆与桥墩等柱类结构物的撞击问题进行了研究。重点探讨了卡车撞击柱类结构物的撞击机理、简化模型、等效试验方法以及防撞设计方法等。
[Abstract]:Many domestic and foreign impact accidents show that when confronted with large vehicle impact, according to the existing design specification of piers may occur and cause failure of the whole bridge collapsed, resulting in two times more serious disaster, and cause the whole road closed long time and other serious consequences. Therefore, research has important practical significance to the problem of vehicle impacting pier; pier collision and how to design a reasonable and effective has become an urgent problem to be solved. This thesis reviewed the analysis of relevant documents, including reinforced concrete beams and columns to study the lateral impact performance of pier protective structure, vehicle collision, vehicle collision of bridge pier column structure well, the United States, Britain and other countries related to the design specifications. Analysis shows that the current pier anti collision of the vehicle is still in its infancy, and many key problems have not been resolved. Such as the impact mechanism of vehicle collision column structure, calculation method and pier collision design vehicle anti impact force vehicle guiding principle. This paper uses a lot of impact on the nonlinear finite element analysis of the truck and the pier was studied. The impact analysis of the truck and the elastic and rigid pier, focuses on the impact behavior of trucks and the impact force curve of the pier section. The result of the impact of size and shape, the impact velocity of truck, truck, road slope, between the lorry and pier stiffness and truck eccentric distance and a series of parameters were studied on the impact effect. In the truck and the elastoplastic finite element of reinforced concrete bridge piers in the analysis, focusing on the finite element simulation of shear failure of reinforced concrete members under the control of the simulation method and the pier, the lower part of the structure of the impact effect So, in order to provide reference for the design of reinforced concrete bridge pier collision. The truck and bridge pier impact is simplified with three degrees of freedom coupling mass spring damping model, namely CMSD model; the first truck is simplified as a parallel double freedom mass spring damping model, the pier is simplified as a single freedom the degree of mass spring damping model. The CMSD model can be used on truck pier collision time history analysis, so as to get the truck impact force, pier pier force, feature point displacement and even deformation trucks and other key information. The CMSD model was analyzed based on a series of parameters, the relation curve of truck quality. Between the impact velocity and impact force and the characteristics of pier or pier bearing force of single degree of freedom model of the truck crash characteristics are taken into account, two degrees of freedom model and CMSD model respectively the reaction Spectrum analysis. The results show that the CMSD model response spectrum and two degrees of freedom model. Finally, based on the similarity of response spectrum fitting double freedom model response spectrum obtained truck collision pier elastic response spectrum, which laid the foundation pier anti collision of the vehicle design. In addition, taking into account the real car collision test cost is high, is presented in this paper. A cheap truck equivalent steel frame test model, used to replace large truck crash test on a column type structure. The internal structure of the model is very simple, only composed of a plurality of groove block made of steel and steel, but it is considered the actual geometrical and physical characteristics of the reference truck. By comparing with the finite element the validation of the fine model truck, truck with equivalent steel frame model similar to the actual impact of the truck. It was also the first time to use the scale (1/3) equivalent model of coagulation truck steel reinforced The drop hammer impact test of soil column, the reinforced concrete column and the equivalent failure mode of the truck frame model was studied. In short, this paper used the finite element analysis, programming and experimental research methods such as impact problems for vehicle and bridge pier column structure is studied. Discussed the impact mechanism of the truck crash the column type structure of the simplified model, equivalent test methods and anti-collision design methods.

【学位授予单位】：湖南大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：U443.26

【参考文献】