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Rail expansion joint with movable stock rail
Rail expansion joint for long extension lengths
Volver a la información general
Rail expansion joint for long extension lengths
Different longitudinal movements in the track can lead to excessive constraining forces in the rail that may cause damage to the superstructure.
In particular, at the transition from one substructure to another substructure, e.g. from a railway embankment to a bridge or from bridge deck to bridge deck, the different longitudinal movements (mainly due to temperature strains but also due to dynamic loads on the bridge) cannot be sufficiently compensated by the superstructure. This is where rail expansion joints (REJs) are used.
The REJ provides long extension lengths (up to ±600mm) with movable stock rails, fixed switch rails, and continuous wheel overrun. The switch rails have an asymmetric rail profile and are fixed elastically. In their moveable section the stock rails are guided on the outside and inside, and are supported laterally. The rail expansion joint is equipped with concrete or wooden sleepers for ballasted track, but is also suitable for slab track. Depending on the requirements, the rail expansion joint can be provided with or without guard rails. In order to compensate for the wider sleeper spacing at a bridge joint, the stock rails are reinforced in this area by additional rails or supported on a steel girder.
Technical description