Reusing life-expired railway ballast: laboratory testing, shape analysis, and petrographic evaluation
Reusing life-expired railway ballast: laboratory testing, shape analysis, and petrographic evaluation
During its service life, railway ballast degrades. Individual grains are abraded, asperities may break off, and the assembly loses performance as the finer material created progressively fouls the assembly. The causes of this are the repeated cyclic loading from passing trains and the major damage caused to ballast by tamping operations to restore track geometry. Eventually the ballast bed requires complete replacement, and recovered trackbed material is disposed of as waste or down-cycled. However, modern ballasts often are formed from stronger parent rocks than in the past, and a proportion may retain sufficient characteristics for reuse. This paper investigated the reuse of recovered life-expired ballast. A series of tests using fresh and reused ballast was carried out using the Southampton Railway Testing Facility (SRTF) and a large triaxial testing apparatus to compare performance. The properties of individual ballast grains were characterized in terms of their shape and petrographic make up. The results show that the type of recovered life-expired ballast used in this study has good performance and similar strength to fresh ballast despite having reduced surface roughness. The petrographic analysis showed that a majority of the recovered ballast was formed of granite, with a significant minority of basalt. These findings may be in contrast to those of some previous studies in which different life-expired rock sources were used, and highlights the importance of the source material.
Ballast, Railway, Roughness, Settlement, Shape, Trackbed, Triaxial
Abadi, Taufan
5e3abda7-80eb-4f39-921e-fae1f472d238
Bangalore Narasimha Murthy, Madhusudhan
e139e3d3-2992-4579-b3f0-4eec3ddae98c
Li, H.
e6f231b5-28cd-425f-b136-55ceab5d00db
Le Pen, L.
4a38e256-d113-4bba-b0d4-32d41995928a
1 January 2023
Abadi, Taufan
5e3abda7-80eb-4f39-921e-fae1f472d238
Bangalore Narasimha Murthy, Madhusudhan
e139e3d3-2992-4579-b3f0-4eec3ddae98c
Li, H.
e6f231b5-28cd-425f-b136-55ceab5d00db
Le Pen, L.
4a38e256-d113-4bba-b0d4-32d41995928a
Abadi, Taufan, Bangalore Narasimha Murthy, Madhusudhan, Li, H. and Le Pen, L.
(2023)
Reusing life-expired railway ballast: laboratory testing, shape analysis, and petrographic evaluation.
Journal of Geotechnical and Geoenvironmental Engineering, 149 (1), [04022123].
(doi:10.1061/(ASCE)GT.1943-5606.0002904).
Abstract
During its service life, railway ballast degrades. Individual grains are abraded, asperities may break off, and the assembly loses performance as the finer material created progressively fouls the assembly. The causes of this are the repeated cyclic loading from passing trains and the major damage caused to ballast by tamping operations to restore track geometry. Eventually the ballast bed requires complete replacement, and recovered trackbed material is disposed of as waste or down-cycled. However, modern ballasts often are formed from stronger parent rocks than in the past, and a proportion may retain sufficient characteristics for reuse. This paper investigated the reuse of recovered life-expired ballast. A series of tests using fresh and reused ballast was carried out using the Southampton Railway Testing Facility (SRTF) and a large triaxial testing apparatus to compare performance. The properties of individual ballast grains were characterized in terms of their shape and petrographic make up. The results show that the type of recovered life-expired ballast used in this study has good performance and similar strength to fresh ballast despite having reduced surface roughness. The petrographic analysis showed that a majority of the recovered ballast was formed of granite, with a significant minority of basalt. These findings may be in contrast to those of some previous studies in which different life-expired rock sources were used, and highlights the importance of the source material.
Text
(ASCE)GT.1943-5606.0002904
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More information
Accepted/In Press date: 17 June 2022
e-pub ahead of print date: 12 November 2022
Published date: 1 January 2023
Additional Information:
Funding Information:
The work described in this paper was jointly funded by the EU via the project In2Rail (Call identifier H2020-MG-2014, Grant Agreement No. 635900) and the UK’s Engineering and Physical Sciences Research Council (EPSRC) as part of the track to the future (T2F) project (Grant Reference EP/M025276/1). The authors thank Network Rail for support in kind (providing the materials for testing and explaining current practice). The authors also acknowledge staff at the UK’s National Oceanography Centre (NOC) for the mineralogical analyses, in particular Dr. Richard Pearce and Dan Doran.
Publisher Copyright:
© 2022 This work is made available under the terms of the Creative Commons Attribution 4.0 International license,.
Keywords:
Ballast, Railway, Roughness, Settlement, Shape, Trackbed, Triaxial
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Local EPrints ID: 473985
URI: http://eprints.soton.ac.uk/id/eprint/473985
ISSN: 1090-0241
PURE UUID: 0d0c86fa-3d1e-4e13-a222-7ffcafa2fecd
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Date deposited: 07 Feb 2023 17:37
Last modified: 06 Jun 2024 01:53
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Author:
H. Li
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