提速货车作用下铁路钢板梁横向振动机理

Lateral Vibration Research of the Deck Steel Plate Bridges under Raised Speed Freight Train

针对我国铁路货车提速过程中发现的铁路上承钢板梁桥横向振动严重超限现象 ,以随机人工蛇行波作为激励输入 ,通过大量的模拟计算 ,对 40m上承钢板梁在货车 (空车 )作用下的横向振动特性进行了初步探讨 ,结果表明 :当输入蛇行波长在 8～ 9m范围内 ,列车行驶速度为 5 5～ 70km·h-1时 ,蛇行运动频率为 2 .10Hz左右 ,正好与梁的横向有载频率接近 ,这时桥梁横向振动出现较大的振幅 。

Since the speeds of the train were raised,the results of field tests of some deck steel plate bridges have shown heavy lateral response amplitude exceeding the anticipation value under the freight train.In this paper,numbers of analysis are carried out for the lateral vibration of 40 m deck steel plate bridges under input of random artificial haunting waves.The result shows that when the length of haunting waves is about 8～9 m and the velocity of the train is about 55～70 km·h -1 ,the frequency of haunting motion is about 2.1 Hz,approaching loaded frequency of the girder.The heavy lateral vibration response is due to the frequency of haunting motion coinciding with loaded frequency of the girder.The results of analysis agree well with the field test data.