| Abstrakt: |
For structural engineers to deliver efficient and robust design solutions, it is essential to understand the performance of each structure for its intended use and for the design life of the asset. When this principle is applied to railway bridges, the structure cannot be assessed in isolation, because bridge behaviour is linked to the railway track on that bridge. For railway bridges, it is essential that structural engineers interface with railway track engineers to understand the general characteristics of the rail so that relevant standards and codes can in turn be used to assess the Rail Structure Interaction (RSI). AS 5100:2017 is the Australian bridge design standard and it provides criteria for the design of railway bridges, including parameters such as applied loads and design actions. However, regarding the interaction between the bridge and the track, some items are still missing or unclear in AS 5100-2017, and there is a major concern that ambiguity can lead to potentially unconservative interpretations that adversely affect the in-service performance of railway bridges. Industry evidence suggests that structural engineers turn to reputable international guidance to address these apparent shortcomings. e.g. UIC, Eurocode, AASHTO, AREMA. It would be preferrable if AS 5100-2017 were updated to incorporate international best practice, but re-appropriated into the Australian context through consultation with Australian railway authorities, bridge engineers, and railway track engineers. This paper offers improvements to AS 5100.2:2017. Suggested improvements include: additional guidance for force-displacement behaviour between track and structure; updates to current wording for the 'rational' and 'empirical' methods; providing design limits for rail performance; adding 'default' rail vehicle loading parameters; adding 'broken rail' and 'operability basis earthquake' load cases; updates to load combinations; and providing detailing requirements. [ABSTRACT FROM AUTHOR] |
