Constriction size distributions of granular filters: a numerical study
File(s)
Published version
Accepted version
Author(s)
Shire, TC
O'Sullivan, C
Type
Journal Article
Abstract
The retention capability of granular filters is controlled by the narrow constrictions connecting the voids within the filter. The theoretical justification for empirical filter rules used in practice includes consideration of an idealised soil fabric in which constrictions form between co-planar combinations of spherical filter particles. This idealised fabric has not been confirmed by experimental or numerical observations of real constrictions. This paper reports the results of direct, particle-scale measurement of the constriction size distribution (CSD) within virtual samples of granular filters created using the discrete-element method (DEM). A previously proposed analytical method that predicts the full CSD using inscribed circles to estimate constriction sizes is found to poorly predict the CSD for widely graded filters due to an over-idealisation of the soil fabric. The DEM data generated are used to explore quantitatively the influence of the coefficient of uniformity, particle size distribution and relative density of the filter on the CSD. For a given relative density CSDs form a narrow band of similarly shaped curves when normalised by characteristic filter diameters. This lends support to the practical use of characteristic diameters to assess filter retention capability.
Date Issued
2016-10-01
Date Acceptance
2016-03-22
Citation
Geotechnique: international journal of soil mechanics, 2016, 66 (10), pp.826-839
ISSN
0016-8505
Publisher
ICE Publishing
Start Page
826
End Page
839
Journal / Book Title
Geotechnique: international journal of soil mechanics
Volume
66
Issue
10
Copyright Statement
This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
License URL
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Identifier
https://www.icevirtuallibrary.com/doi/10.1680/jgeot.15.P.215
Grant Number
EP/I006761/1
Subjects
Science & Technology
Technology
Engineering, Geological
Engineering
discrete-element modelling
filters
POROUS-MEDIA
FILTRATION
NETWORK
DESIGN
SOILS
SAND
0905 Civil Engineering
0907 Environmental Engineering
0914 Resources Engineering and Extractive Metallurgy
Geological & Geomatics Engineering
Publication Status
Published
Date Publish Online
2016-06-10