Relating Hydraulic Conductivity to Particle Size Using DEM
Publication: International Journal of Geomechanics
Volume 21, Issue 1
Abstract
For over 100 years it has been accepted that the permeability or hydraulic conductivity of a soil is controlled by the size of pores through which the fluid flows, and that this pore size should be a function of particle sizes. All well-known formulas (such as the empirical Hazen or analytical Kozeny–Carman) are based on the squared value of some characteristic particle or pore size. Recent work has established which particles control the porosity or density of a granular material, so it follows that these particles may also govern the hydraulic conductivity. In this work, a new yet simple technique was used to obtain a characteristic “smallest” particle size, which is a function of both the particle size distribution and the geometrical packing. The use of this new proposed characteristic particle size was shown to be valid both theoretically and in comparison with the characteristic particle or pore sizes used in classical predictive methods for the permeability of granular materials. A very simple fractal theory showed what the characteristic particle size that controls conductivity should be, and a simple discrete element simulation was used to confirm the result.
Formats available
You can view the full content in the following formats:
Acknowledgments
This work was supported by the Engineering and Physical Sciences Research Council (Grant number EP/L019779/1).
Notation
The following symbols are used in this paper:
- D
- fractal dimension;
- d
- particle size (diameter);
- dp
- pore size;
- dpi
- pore size corresponding to inflection point on distribution;
- dsm
- size of the smallest particles;
- d10
- particle size for which 10% are smaller;
- e
- void ratio;
- k
- hydraulic conductivity;
- N
- number of particles;
- n
- porosity;
- rh
- hydraulic radius;
- S
- surface area per unit volume of bulk material;
- ST
- total surface area of solids;
- S0
- specific surface area (surface area per unit volume of solid material);
- VS
- volume of solids;
- Vsm
- cumulative volume of the smallest particles; and
- Vv
- volume of voids.
References
Anishchik, S. V., and N. N. Medvedev. 1995. “Three-dimensional apollonian packing as a model for dense granular systems.” Phys. Rev. Lett. 75 (23): 4314–4317.
Bolton, M. D. 1986. “The strength and dilatancy of sands.” Géotechnique 36 (1): 65–78.
Bryant, S., and M. Blunt. 1992. “Prediction of relative permeability in simple porous media.” Phys. Rev. A 46 (4): 2004–2011.
Burmister, D. M. 1938. Vol. 38 of The grading-density relations of granular materials, 587–601. Philadelphia: ASTM.
Carman, P. C. 1956. Flow of gases through porous media. New York: Academic Press.
Carrier, W. D. 2003. “Goodbye, Hazen; Hello, Kozeny-Carman.” J. Geotech. Geoenviron. Eng. 129 (11): 1054–1056. https://doi.org/10.1061/(ASCE)1090-0241(2003)129:11(1054).
Chapuis, R. P. 2012. “Predicting the saturated hydraulic conductivity of soils: A review.” Bull. Eng. Geol. Environ. 71 (3): 401–434.
de Bono, J. P., and G. R. McDowell. 2018a. “Validation of the log e–log σ normal compression law using particle strength data.” Géotechnique 68 (5): 451–456.
de Bono, J. P., and G. R. McDowell. 2018b. “On the packing and crushing of granular materials.” Int. J. Solids Struct. 187: 133–140.
Hazen, A. 1892. Some physical properties of sands and gravels with special reference to their use in filtration. 24th Annual Rep. Publication Doc No. 34, 539–556. Boston: Massachusetts State Board of Health.
Katz, A. J., and A. H. Thompson. 1986. “Quantitative prediction of permeability in porous rock.” Phys. Rev. B 34 (11): 8179–8181.
McDowell, G. R. 2005. “A physical justification for log e–log σ based on fractal crushing and particle kinematics.” Géotechnique 55 (9): 697–698.
McDowell, G. R., and M. D. Bolton. 1998. “On the micromechanics of crushable aggregates.” Géotechnique 48 (5): 667–679.
McDowell, G. R., and J. P. de Bono. 2013. “On the micro mechanics of one-dimensional normal compression.” Géotechnique 63 (11): 895–908.
Mitchell, J. K., and K. Soga. 2005. Fundamentals of soil behavior. Hoboken, NJ: John Wiley and Sons.
Nelson, P. H. 2009. “Pore-throat sizes in sandstones, tight sandstones, and shales.” AAPG Bull. 93 (3): 329–340.
Palmer, A. C., and T. J. O. Sanderson. 1991. “Fractal crushing of ice and brittle solids.” Proc. R. Soc. A 433 (1889): 469–477.
Turcotte, D. L. 1986. “Fractals and fragmentation.” J. Geophys. Res. 91 (B2): 1921.
Information & Authors
Information
Published In
Copyright
This work is made available under the terms of the Creative Commons Attribution 4.0 International license, https://creativecommons.org/licenses/by/4.0/.
History
Received: Feb 6, 2019
Accepted: Nov 4, 2019
Published online: Oct 23, 2020
Published in print: Jan 1, 2021
Discussion open until: Mar 23, 2021
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.