Effect of under sleeper pads on railway track subgrade

Kamalov, Rafael (2021). Effect of under sleeper pads on railway track subgrade. University of Birmingham. Ph.D.

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The subgrade layer is designed to provide a stable foundation and carry the load of an entire railway track structure. The migration of fine particles from the cohesive subgrade layer into the overlying ballast is a common and significant problem in the railway industry. Under repeated loading, the ballast voids become filled with subgrade cohesive material that reduces the ballast’s permeability, which then further increases the chances of problems such as mud pumping and subgrade deformation. This research work studied the effect of the under-sleeper pads (the USPs) on subgrade deformation, stiffness and erodibility. Four cohesive soils were tested in a small-scale cyclic test. The effects of the moisture content and the strength of the subgrade were investigated. The whole system has been subjected to repeated loading over 200,000 cycles under conditions simulating a railway. To validate the data received from the small-scale test, several tests were run on a large-scale apparatus. Laboratory testing has been carried out employing a set-up resembling a railway cross-section. The received data enabled analysis of the trends in the permanent and cyclic subgrade deformations. The amount of eroded soil, the stiffness and strength of the soil (before and after the test), and the development of pore water pressure were investigated. The results show that applying the USP has an overall beneficial effect on the subgrade layer, reducing the level of permanent deformation and reducing the amount of eroded soil. The large-scale tests showed similar trends in terms of permanent deformation and soil stiffness, which suggested that the small-scale test results correlate well with railway track conditions.

Type of Work: Thesis (Doctorates > Ph.D.)
Award Type: Doctorates > Ph.D.
Licence: All rights reserved
College/Faculty: Colleges (2008 onwards) > College of Engineering & Physical Sciences
School or Department: School of Civil Engineering
Funders: None/not applicable
Subjects: T Technology > TA Engineering (General). Civil engineering (General)
T Technology > TE Highway engineering. Roads and pavements
T Technology > TF Railroad engineering and operation
URI: http://etheses.bham.ac.uk/id/eprint/12120

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  • Effect of under sleeper pads on railway track subgrade. (deposited 05 Dec 2022 10:41) [Currently Displayed]


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