Title Expanding our understanding of the not so insignificant rail expansion joint
Author Matthews, A
Affiliation GHD
Publication Date 2021
Conference CORE 2021: Collaborating to Master Complexity: Conference on Railway Excellence, 21-23 June 2021, Perth, WA, Australia
Abstract The humble rail expansion joint, also known as an expansion switch, breather switch, has been employed around the world in the broader rail industry for many years. However, some recent local projects have highlighted the industry’s lack of understanding of when and how they should be implemented. There are a number of different types of expansion joints available and they each have their applications and limitations. The application of rail expansion joints/breather switches has proved to be a challenge on Metro projects with elevated corridors, where slab track form of construction has been adopted. The distance and orientation of the breather switch in relation to the viaduct structure expansion joint is crucial to the success in resolving differential movement. The relationship between structure movement joints and special track work can also be a significant issue. There are also a number of circumstances where rail expansion joints are employed on conventional ballasted track form, in addition to where jointed track interfaces with continuously welded rail (CWR). This paper highlights some examples of the successful and not so successful implementation of rail expansion joints/breather switches. It describes how a better understanding of the actual mechanical function in relation to rail and structure movement, and of the various joint types, could have significantly improved the project outcomes. Applications relating to bridges and viaducts, track stressing and ground movement are discussed, in both heavy rail and light rail environments. The various types of expansion joint are analysed and their operational constraints described. This paper also challenges the functional performance of a mainstream breather switch standard design and its application to a recently constructed metro project. This paper aims to improve the understanding of rail expansion joints and consequently enable a more appropriate detailing of solutions where rail movement must be accommodated.
File - click thumbnail to download
CORE 2021_Matthews
Physical Description 16p. ; PDF
Subjects Railway track
Expansion joint
Switch
Bearings
Slab
Welding
Design
Location ARRB library
Category Rail Knowledge Bank Index Infrastructure Track Track design