列车-地震作用下桥梁结构的动力分析

当列车行驶在桥梁上,同时又遭遇地震作用时,二者的振动叠加或在某个时刻产生共振,会对桥梁结构产生很大破坏。针对这一问题,本文以新建铁路德龙烟线德州至大家洼段64m钢桁架桥梁为例,通过特征值分析,得到了所建模型各阶振动模态及其频率,并分别在地震和列车荷载单独作用时进行时程分析,同时分析了二者共同作用下的动力响应。分析结果表明,结构的第一阶振型为横向一阶,所以结构对于横向地震作用及列车荷载横向动力作用响应显著;地震作用与列车荷载作用相比,其在不同于加载方向产生的响应较小,两者共同作用时,响应明显变大。该研究为桥梁动力设计提供了理论依据。

Dynamic Analysis of Bridge Structure Under Train and Earthquake Action

When the train is just running on the bridge under earthqu ake action, the bridge structure may To analyze this problem, a 64m steel s paper. Firstly, vibration mode and tory analysis under moving train load onses under the two actions together are analyzed. The following conclusions are drawn, because the first-order mode of this bridge is lateral one-order vibration, lateral dynamic response of this structure is more obvious under earthquake action and lateral dynamic excitation of train running load; seismic response in the directions different from train load is small, and dynamic response is obvious under the two actions together. In this paper, the dynamic anal- ysis of the upper structure under the train load and earthquake provides some beneficial conclusions for bridge dynamic design and also provides the basis for the future study.