Mitigating ballast degradation with under-sleeper rubber pads: Experimental and numerical perspectives

Ngo, T; Indraratna, B

Mitigating ballast degradation with under-sleeper rubber pads: Experimental and numerical perspectives

Ngo, T Indraratna, B

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Publisher:: ELSEVIER SCI LTD
Publication Type:: Journal Article
Citation:: Computers and Geotechnics, 2020, 122
Issue Date:: 2020-06-01

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Field	Value	Language
dc.contributor.author	Ngo, T
dc.contributor.author	Indraratna, B https://orcid.org/0000-0002-9057-1514
dc.date.accessioned	2021-03-07T02:49:30Z
dc.date.available	2021-03-07T02:49:30Z
dc.date.issued	2020-06-01
dc.identifier.citation	Computers and Geotechnics, 2020, 122
dc.identifier.issn	0266-352X
dc.identifier.issn	1873-7633
dc.identifier.uri	http://hdl.handle.net/10453/146836
dc.description.abstract	© 2020 Elsevier Ltd This paper presents a study on mitigating the degradation of ballast by placing an under-sleeper rubber pad (USP) beneath a sleeper. Large-scale track process simulation apparatus (TPSA) tests have been carried out on ballast assemblies (with and without USP) subjected to cyclic loadings. Numerical modelling has been performed using a coupled discrete-continuum modelling (coupled DEM-FDM) approach to investigate the role of USP from a micromechanical perspective. Ballast grains are simulated in DEM by bonding of many cylinders together at appropriate sizes and locations; and when those bonds break, they are considered to represent ballast breakage. The capping and subgrade layers are simulated as continuum media using the finite difference method (FDM). Interface elements were developed for transmitting forces and displacements between the discrete and continuum domains. The coupled model is validated by comparing the predicted load-deformation responses with those measured from large-scale TPSA tests. The model is then used to explore changes in the micromechanical aspects of ballast subjected to cyclic loading, including particle connectivity number, contact force distributions, and contact orientations and associated particle breakage. These findings are needed to gain a better insight as to how USPs help to attenuate the load applied in a ballast assembly.
dc.language	English
dc.publisher	ELSEVIER SCI LTD
dc.relation	http://purl.org/au-research/grants/arc/IC170100006
dc.relation.ispartof	Computers and Geotechnics
dc.relation.isbasedon	10.1016/j.compgeo.2020.103540
dc.rights	info:eu-repo/semantics/closedAccess
dc.subject	0905 Civil Engineering, 0914 Resources Engineering and Extractive Metallurgy, 0915 Interdisciplinary Engineering
dc.subject.classification	Geological & Geomatics Engineering
dc.title	Mitigating ballast degradation with under-sleeper rubber pads: Experimental and numerical perspectives
dc.type	Journal Article
utslib.citation.volume	122
utslib.for	0905 Civil Engineering
utslib.for	0905 Civil Engineering
utslib.for	0914 Resources Engineering and Extractive Metallurgy
utslib.for	0915 Interdisciplinary Engineering
pubs.organisational-group	/University of Technology Sydney/Faculty of Engineering and Information Technology
pubs.organisational-group	/University of Technology Sydney/Faculty of Engineering and Information Technology/School of Civil and Environmental Engineering
pubs.organisational-group	/University of Technology Sydney
utslib.copyright.status	closed_access	*
dc.date.updated	2021-03-07T02:49:16Z
pubs.publication-status	Published
pubs.volume	122

Abstract:

© 2020 Elsevier Ltd This paper presents a study on mitigating the degradation of ballast by placing an under-sleeper rubber pad (USP) beneath a sleeper. Large-scale track process simulation apparatus (TPSA) tests have been carried out on ballast assemblies (with and without USP) subjected to cyclic loadings. Numerical modelling has been performed using a coupled discrete-continuum modelling (coupled DEM-FDM) approach to investigate the role of USP from a micromechanical perspective. Ballast grains are simulated in DEM by bonding of many cylinders together at appropriate sizes and locations; and when those bonds break, they are considered to represent ballast breakage. The capping and subgrade layers are simulated as continuum media using the finite difference method (FDM). Interface elements were developed for transmitting forces and displacements between the discrete and continuum domains. The coupled model is validated by comparing the predicted load-deformation responses with those measured from large-scale TPSA tests. The model is then used to explore changes in the micromechanical aspects of ballast subjected to cyclic loading, including particle connectivity number, contact force distributions, and contact orientations and associated particle breakage. These findings are needed to gain a better insight as to how USPs help to attenuate the load applied in a ballast assembly.

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http://hdl.handle.net/10453/146836