基于LS-DYNA的车-桥墩碰撞及可靠度研究  

Study on Vehicle-pier Collision and Reliability Based on LS-DYNA

作　　者：王向阳[1] 吴琼[1,2] 张林凯 WANG Xiang-yang;WU Qiong;ZHANG Lin-kai(School of Transportation,Wuhan University of Technology,Wuhan Hubei 430063,China;Hubei Transportation Planning and Design Institute Co.,Ltd.,Wuhan Hubei 430051,China)

机构地区：[1]武汉理工大学交通学院,湖北武汉430063 [2]湖北省交通规划设计院股份有限公司,湖北武汉430051

出　　处：《公路交通科技》2020年第5期64-72,共9页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(51178361);湖北省自然科学基金项目(2013CFB342)

摘　　要：桥墩受到车辆碰撞后会产生不同程度的损伤,因此研究车-桥墩碰撞后的受力特性和可靠度具有很好的现实意义。首先以某连续梁桥为背景,建立了车-桥墩碰撞有限元模型,其中撞击车辆为常用卡车,材料为钢材,采用弹塑性本构关系。桥墩为双柱式墩,通过典型工况研究了桥墩遭受车辆撞击后墩柱体的剪应力、主应力等的发展规律和时间历程。然后采用一系列车-桥墩碰撞作用,拟合出车撞力计算公式,通过与其他文献及多国规范比较,表明了拟合公式的正确性。再将拟合公式代入模型,考虑某些参数为随机变量,分析了车辆与桥墩碰撞后的结构体系可靠度。结构体系由3个双柱式桥墩组成,其中任何一个双柱式墩破坏意味着整个结构破坏。双柱桥墩中两个墩柱视为串联体系,即一个墩柱失效则双柱墩失效。最后研究了各随机变量对单墩抗剪性能可靠性指标的敏感性。研究结果表明:桥墩在横桥向或顺桥向车撞力作用下均更容易发生剪切破坏,而桥墩墩底易发生弯曲破坏,墩底关键截面内力满足正态分布;混凝土强度对墩柱抗剪承载力可靠性指标的影响最大,在桥梁施工以及管理过程中需要重点关注结构混凝土强度变化。It is important to study the mechanical characteristics and reliability of vehicle-pier collision because pier will be damaged in different degrees after vehicle collision. First, on the background of a continuous beam bridge, the FE model of vehicle-pier collision is established, in which the vehicle is a common truck, its material is steel, and elastic-plastic constitutive relation is adopted. The pier is a double-column type, its development regularities and processes of shear stress and main stress of the columns after collision are studied through typical working conditions. Second, the calculation formula of vehicle collision force is fitted by a series of vehicle pier collision effect, which is proved correctly by comparing with other literatures and many foreign specifications. And then, substitute the fitting formula into the model, the reliability of the structural system after vehicle-pier collision is analyzed regarding some parameters as random variables. The system is composed of 3 double-column piers, where the failure of any double-column pier means the whole structure failure. The 2 piers in the double-column pier are considered as a series system, that is, if one pier fails, the double-column pier fails. Finally, the sensitivity of variables to the reliability indicator of single pier shear performance is studied. The result shows that(1) piers are more prone to shear failure under transverse or longitudinal vehicle collision, while the pier bottom is prone to bending failure, and the internal forces in key sections at the bottom of piers meet the normal distribution;(2) the influence of concrete strength on the reliability indicator of the pier column shear resistance is the biggest, which should be paid more attention in bridge construction and management.

关 键 词：桥梁工程 车-桥墩碰撞分析 有限元模型 可靠度 敏感性分析 

分 类 号：U443.26[建筑科学—桥梁与隧道工程]