Author(s)

H. M. Kim, S. I. Kim & W. S. Hwang

Abstract

This study investigates the effects of rail joints on the dynamic behaviour of railroad bridges through a dynamic experiment. The subject bridge is a typical steel plate girder railroad bridge. The bridge is 53.4m long, and consists of four simply supported spans (4@12.10m). Rail joints are positioned in the third span. It is 1.8m away from the starting point of the third span. The regular service train applied the dynamic loading. The test train is composed of one diesel locomotive and seven passenger carriages, which is commonly running on the existing railroad lines in Korea. The range of measured speed is from 19.1 to 124.0km/hr. Accelerometers are installed at the bottom flange of the centre of the third span to acquire a bridge response caused by the rail joint. For comparison, another accelerometer is installed at the same position of the first span, which has no rail joint. From the measured results, Peak vale (PV), root mean square (RMS) and dynamic amplification factor (DAF) value analysis are performed in order to compare the instantaneous maximum and mean amplitude of acceleration at each span. The result shows a significant increase in the acceleration of the span with joints. In addition, DAF is from 0.22 to 1.92 for the measured speed zone. The result also shows that rail joints on a bridge produce an impact effect. Thus, it increases the dynamic response of the bridge and deteriorates ride comfort. Keywords: rail joint, acceleration, impact load, dynamic amplified factor, steel plate girder railroad bridge.

Keywords

rail joint, acceleration, impact load, dynamic amplified factor, steel plate girder railroad bridge