Collision derailments on bridges containing ballastless slab tracks

Abstract

Train derailment on bridges is an infrequent event, yet when it occurs, it's usually catastrophic. These incidents can toss-out part of the derailed train from the bridge deck and collapse whole or a part of the bridge. Understanding the derailment mechanisms of trains on bridges and identifying the dynamic characteristics of bridges subjected to the impact of the derailed train is fundamental to minimising severities of these incidents. This paper presents the formulation of a train-track-bridge interaction model for predicting the response of bridges under in-service operation and post-derailment behaviour. The model is used to illustrate the collision induced derailment mechanisms of a passenger train travelling on a box girder bridge; the effect of impact due to the derailed train to the dynamic response of the bridge is also narrated. The nonlinear behaviour of the train-track-bridge system under derailment impacts is detailed through the sensitivity of the wheel/rail contact and the suspension components of the train as well as the parameters of the slab-track. It is shown that the risk of the derailed vehicles being tossed out of the slab-track bridge is high although the bridge deformation and bending moment are low.