Investigating the dynamic behaviour of a railway bridge subjected to over-height vehicle collision

Full service without defects of railway bridges is more important than highway bridges because failure at a part of the bridge results in the blockage of the entire track and the stopping of the trains. In recent years, the problem of an over-height vehicle collision to the bridge superstructure has occurred more frequently. These collisions damage the bridge superstructure and affect the safety of the train causing many problems in railway transportation. In this study, first, a model of the concrete girder bridge was used to validate the effect of the collision load applied to the bottom of the concrete girder bridge. Then, the dynamic responses of the railway bridge simulated as concrete girders and bridge deck also track including rail, sleeper, and ballast are presented by using the finite element method. Finally, the different sensitivity analyses express that changing the bridge span length, and the value of collision loads affect the concrete girder lateral displacement at the contact area. The results show that the lateral displacements decrease with increasing the span length. Additionally, by increasing the collision forces due to increasing the velocity of the impacting object, the lateral displacement at the bottom of the girder reduces.