A型高墩大跨混凝土连续刚构桥车桥动力分析

Vehicle- bridge Coupling Dynamic Analysis of A- type Continuous Rigid Frame Concrete Bridge with High Piers and Long Span

研究目的:针对A型高墩大跨混凝土连续刚构桥,具有墩高、跨度大、墩身体量轻、刚度相对小等特点,分析车桥耦合动力响应,得出车桥动力性能指标,探讨桥梁结构横向自振周期与车桥动力响应的关系。研究结论:(1)结构基频为纵向振动,频率为0.401 Hz,第二振型为横向振动,频率为0.657 Hz,一阶竖弯频率为1.125 Hz;(2)客车以200 km/h运行,车辆运行安全性和平稳性满足要求,横向及竖向舒适度指标均为优良;货车以120 km/h运行,能满足车辆运行安全性和平稳性要求;A型高墩能较好地解决大跨度连续刚构桥的动力性能问题;(3)桥梁横向第一自振周期对桥梁横向振幅影响较大,对梁体竖向、横向加速度影响规律不明确;(4)车辆响应对桥梁横向自振周期不敏感,采用桥梁横向自振周期来反映桥上车辆的运行安全性、舒适性和平稳性的规律性不明显,两者的相关性不显著;(5)本文分析成果对高墩大跨铁路桥梁设计具有指导意义。

Research purposes： A - type continuous rigid frame concrete bridge with high piers and long span has the characteristics of high piers, long span, light pier body weight, relatively small stiffness. The vehicle - bridge coupling dynamic response is analyzed, the vehicle -bridge dynamic performance is got, the relationship between bridge transverse vibration period and vehicle bridge dynamic response is discussed. Research conclusions：（ 1 ）The fundamental frequency of structure is longitudinal vibration, and the frequency is 0. 401 Hz, the second modes is transverse vibration, and the frequency is 0. 657 Hz, the first -order vertical bending frequency is 1. 125 Hz. （2） When the passenger train runs at 200 km/h, the requirements of the vehicle running safety and stability can be met, and the transverse and vertical comfort indexs are excellent; When the freight train runs at 120 km/h, the requirements of the vehicle running safety and stability can be met ; A - type high piers can better solve the problem of dynamic performance of long - span continuous rigid frame bridge. （3） The first bridge transverse vibration period has a greater influence on the bridge transverse amplitude, but the effect of vertical, transverse acceleration of the beam body is not clear. （4） The vehicle response on bridge transverse vibration period is not sensitive, the rule that the bridge transverse vibration period reflect the operation safety, comfort and stationarity of vehicles on the bridge is not obvious, and no significant correlation between the two exists. （5） This paper has a certainguiding significance for the design of railway bridge with high piers and long - span.