单轨与道路交通两用斜拉桥冲击系数研究

Research on Impact Coefficient of Highway and Light-railway Cable-stayed Bridges

桥梁冲击系数与桥梁计算跨径、结构形式、路面状况、行车参数等多种因素有关。对于复杂桥梁,冲击系数的实测值与规范值往往存在较大差异。以某单轨与道路交通两用斜拉桥为工程背景,运用车桥耦合数值模拟的方法,对该桥的局部冲击系数和整体冲击系数进行了分析研究。结果表明:斜拉桥各个构件冲击系数存在较大差异,数值仿真计算的的冲击系数也与规范计算值不同;对于结构和荷载复杂的桥梁,宜具体分析各构件的冲击系数,以免设计趋于保守或偏不安全;对于该类公轨两用斜拉桥的主梁冲击系数取值,单轨交通设计规范规定的冲击系数取值较为合理。

The impact coefficient is connected with the span, structure type? road surface condition, vehicle parameters and some other factors. The experimental value and code value of impact coefficient is often different especially for complex bridge. In this article,the vehicle-bridge coupled numerical model was used to research the local and global impact coefficient of a highway and light-railway cable-stayed bridge. The results indicate that: the impact coefficient is greatly different from each structural member, calculated value and the code value is also different; For complex bridge,it is suggested to adopt different impact factor for each structural member in order to ensure safety and economy; For this kind of cable-stayed bridge, it is reasonable to adopt impact coefficient according to Code for design of straddle transit.