Modelling railway ballasted track settlement in vehicle-track interaction analysis
Modelling railway ballasted track settlement in vehicle-track interaction analysis
The geometry of a ballasted railway gradually deteriorates with trafficking, mainly as a result of the plastic settlement of the track-bed (ballast and sub-base). The rate and amount of settlement depend on a number of factors, and for various reasons are difficult to predict or estimate analytically. As a result, various empirical equations for estimating the rate of development of plastic settlement of railway track with train passage have been proposed. A review of these equations shows that they (i) do not reproduce the form of settlement vs number of load cycles relationships usually seen in the field; (ii) do not reflect current knowledge of the behaviour of soil subgrades in cyclic loading; and (iii) are often critically dependent on the curve fitting parameters used, which in turn depend on the circumstances in which the calibration data were obtained. To address these shortcomings, this paper develops a semi-analytical approach, based on the known behaviour of granular materials under cyclic loading, for the calculation of plastic settlements of the trackbed with train passage. The semi-analytical model is then combined with a suitable vehicle-track interaction analysis to calculate rates of development of permanent settlement for different initial trackbed stiffnesses, vehicle types and speeds. The model is shown to be able to reproduce recursive effects, in which a deterioration in track geometry causes an increased variation in dynamic load, which feeds back into a further deterioration in track geometry. The new model represents a significant improvement on current empirical equations, in that it is able to reproduce observed aspects of railway track settlement on the basis of the known behaviour of soils and ballast in cyclic loading.
Ballast permanent settlement, Ballast settlement model, Iterative routine, Railway ballast, Trackbed stiffness, Vehicle-track interaction
Grossoni, Ilaria
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Powrie, William
600c3f02-00f8-4486-ae4b-b4fc8ec77c3c
Zervos, Antonios
9e60164e-af2c-4776-af7d-dfc9a454c46e
Bezin, Yann
65a989a7-bfce-42aa-be47-0fc19baef291
Le Pen, Louis
4a38e256-d113-4bba-b0d4-32d41995928a
January 2021
Grossoni, Ilaria
d6a76c4a-442e-4272-81bc-5374bee4de86
Powrie, William
600c3f02-00f8-4486-ae4b-b4fc8ec77c3c
Zervos, Antonios
9e60164e-af2c-4776-af7d-dfc9a454c46e
Bezin, Yann
65a989a7-bfce-42aa-be47-0fc19baef291
Le Pen, Louis
4a38e256-d113-4bba-b0d4-32d41995928a
Grossoni, Ilaria, Powrie, William, Zervos, Antonios, Bezin, Yann and Le Pen, Louis
(2021)
Modelling railway ballasted track settlement in vehicle-track interaction analysis.
Transportation Geotechnics, 26, [100433].
(doi:10.1016/j.trgeo.2020.100433).
Abstract
The geometry of a ballasted railway gradually deteriorates with trafficking, mainly as a result of the plastic settlement of the track-bed (ballast and sub-base). The rate and amount of settlement depend on a number of factors, and for various reasons are difficult to predict or estimate analytically. As a result, various empirical equations for estimating the rate of development of plastic settlement of railway track with train passage have been proposed. A review of these equations shows that they (i) do not reproduce the form of settlement vs number of load cycles relationships usually seen in the field; (ii) do not reflect current knowledge of the behaviour of soil subgrades in cyclic loading; and (iii) are often critically dependent on the curve fitting parameters used, which in turn depend on the circumstances in which the calibration data were obtained. To address these shortcomings, this paper develops a semi-analytical approach, based on the known behaviour of granular materials under cyclic loading, for the calculation of plastic settlements of the trackbed with train passage. The semi-analytical model is then combined with a suitable vehicle-track interaction analysis to calculate rates of development of permanent settlement for different initial trackbed stiffnesses, vehicle types and speeds. The model is shown to be able to reproduce recursive effects, in which a deterioration in track geometry causes an increased variation in dynamic load, which feeds back into a further deterioration in track geometry. The new model represents a significant improvement on current empirical equations, in that it is able to reproduce observed aspects of railway track settlement on the basis of the known behaviour of soils and ballast in cyclic loading.
Text
TRGEO100433 authors PDF
- Accepted Manuscript
More information
Accepted/In Press date: 18 August 2020
e-pub ahead of print date: 9 September 2020
Published date: January 2021
Additional Information:
Funding Information:
This work was funded by the UK EPSRC project Track to the Future (grant agreement no. EP/M025276/1 ). The authors are grateful to Dr Taufan Abadi, Dr Edgar Ferro and Mr Giacomo Ognibene for their assistance with the review of track settlement equations, and to Dr Taufan Abadi for his help in compiling the Appendix. The data used in the creation of the original figures presented in this paper are available at https://doi.org/10.5258/SOTON/D1540 .
Publisher Copyright:
© 2020 The Authors
Keywords:
Ballast permanent settlement, Ballast settlement model, Iterative routine, Railway ballast, Trackbed stiffness, Vehicle-track interaction
Identifiers
Local EPrints ID: 443746
URI: http://eprints.soton.ac.uk/id/eprint/443746
ISSN: 2214-3912
PURE UUID: 32e7a251-35b2-4b28-bc91-d9bbb9faa565
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Date deposited: 10 Sep 2020 16:47
Last modified: 17 Mar 2024 03:03
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Author:
Ilaria Grossoni
Author:
Yann Bezin
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