Bridges

Railway bridges and structures collision protection requirements are covered in many standards and codes across Australia and around the world. Design preference for bridges over railways is to have a clear span between abutments and to have supports at least 20 m clear of tracks. However, due to many site constraints, particularly for existing bridge modifications and at railway stations, fully satisfying standard requirements may not be reasonably practicable.

AS 5100, being the primary Australian Standard covering railway bridge collision protection is also supplemented by relevant state transport authority standards and documents to address the multiple scenarios of bridge configurations and site variables. Associated with these many possibilities, AS 5100 has over twenty references back to the 'relevant authority' and nine references to a 'risk assessment' to resolve design decisions such as loading, geometry and available platform wall resistance predominately using lessons learnt from historical events and data, including catastrophic accidents. Also, AS 5100 only has very limited guidance for bridge supports on railway station platforms.

This paper provides an insight and compares standard requirements published within Australia and some key international codes such as UIC-777-2R associated with bridges over railways with supports at station platforms and presents a simple summary table of the results, together with recommendations. The aim is to assist bridge and transport asset managers to easily compare design requirements for overbridge, footbridge and airspace development collision protection at railway stations.