New Perspectives on Running Safety in Ballastless Railway Bridges

Abstract

Running safety on ballastless bridges is conditioned by the Eurocode EN 1990 A2 on a limit for vertical acceleration. Although it seems this limit is indicative of avoiding the loss of wheel-rail contact, it is unclear whether such accelerations correspond to derailment situations. This communication presents a parametric study of five single-span slab track bridges with varying levels of track quality. Using the High- Speed Load Model A of the EN 1991-2 and a three-dimensional train-track-bridgeinteraction approach, deck acceleration and derailment criteria (Nadal and Unloading) are calculated. The results indicate a poor correlation between acceleration and the criteria. It is concluded that track quality is the conditioning factor.