The Open UniversitySkip to content
 

Steady-state ditch-drainage of two-layered soil regions overlying an inverted v-shaped impermeable bed with examples of the drainage of ballast beneath railway tracks

Youngs, E. G. and Rushton, K. R. (2009). Steady-state ditch-drainage of two-layered soil regions overlying an inverted v-shaped impermeable bed with examples of the drainage of ballast beneath railway tracks. Journal of Hydrology, 377(3-4) pp. 367–376.

Full text available as:
[img]
Preview
PDF (Accepted Manuscript) - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Download (871Kb)
DOI (Digital Object Identifier) Link: http://dx.doi.org/10.1016/j.jhydrol.2009.08.034
Google Scholar: Look up in Google Scholar

Abstract

Water-table heights due to steady surface accretion in drained two-layered soil regions overlying an inverted V -shaped impermeable bed are obtained using both the Dupuit-Forchheimer approximate analysis with flow assumed parallel to the bed and also from numerical solutions of Laplace's equation for the head distribution. For illustration, water-table profiles obtained by the two procedures are compared for surface accretion draining to ditches in a typical two-layered ballast foundation for a railway track where a very permeable ballast material overlies a less permeable sub-grade on top of an inverted V-shaped impermeable bed that slopes away both sides from a central line to drainage ditches. These results are found to be in good agreement except very near the drainage ditches where the Laplace numerical solution takes into consideration a surface of seepage that is ignored in the Dupuit-Forchheimer analysis. The Dupuit-Forchheimer analysis is also in good agreement with results of a laboratory model experiment. It is concluded that the approximate Dupuit-Forchheimer analysis can be used with confidence in these situations. It is used to investigate the effect on the water-table elevation caused by the reduction of hydraulic conductivity of the porous materials due to clogging.

Item Type: Journal Article
Copyright Holders: 2009 Elsevier B.V.
ISSN: 0022-1694
Keywords: drainage; layered soils; sloping bed; Dupuit-Forchheimer analysis; Laplace numerical solutions; railway ballast beds
Academic Unit/Department: Science > Environment, Earth and Ecosystems
Item ID: 18367
Depositing User: Colin Smith
Date Deposited: 07 Sep 2009 15:41
Last Modified: 23 Oct 2012 20:06
URI: http://oro.open.ac.uk/id/eprint/18367
Share this page:

Altmetrics

Scopus Citations

Actions (login may be required)

View Item
Report issue / request change

Policies | Disclaimer

© The Open University   + 44 (0)870 333 4340   general-enquiries@open.ac.uk