城市桥梁新型桥侧混凝土护栏的碰撞分析

以某城区高架桥为例,设计出一种城市桥梁新型桥侧混凝土护栏的最优结构,并采用有限元仿真与碰撞试验相结合的方法对其进行安全防护性能分析。结果表明,新型桥侧混凝土护栏结构能够有效地防护行驶车辆,其中小客车碰撞后,其驶出角度为7°,大客车碰撞后,其驶出角度为1.7°;小客车碰撞后,其重心加速度最大值为17.4g,大客车碰撞后,护栏的最大动态变形小于100mm;混凝土坡面是影响小客车缓冲保护性能的主要因素,混凝土墙体强度是影响大客车防撞性能的主要因素。新型桥侧混凝土护栏的各项指标均满足评价标准,其防撞等级达到SS级,且成功应用于依托工程。

Impact analysis of a new type of roadside concrete barrier for urban bridges

The optimal structure of a new type of roadside concrete barrier for an urban elevated bridge was designed and the safety evaluation of the structure was conducted by the combined approach of finite element simulation and impact test. The results show that the new structure can effectively block vehicles with better guidance. After the collision, the angle of cars pulled out is 7° and that of buses is 1.7°. The maximum acceleration of cars after the collision is 17.4g, and the maximum dynamic deformation of the barrier after bus collision is less than 10cm. It is also found that concrete slope is a major factor affecting buffer protection of cars, and the strength of concrete wall is a major factor affecting crashworthiness of buses. The new type of city bridge roadside concrete barriers meets the evaluation criteria in all indexes, reaching SS-level in crash rating, and has been applied to relying project successfully.