Authors: Doherty, JP


Cite As:
Doherty, JP 2014, 'The impact of pore pressure boundary conditions in stope backfilling models', in Y Potvin & T Grice (eds), Mine Fill 2014: Proceedings of the Eleventh International Symposium on Mining with Backfill, Australian Centre for Geomechanics, Perth, pp. 113-120,

Download citation as:   ris   bibtex   endnote   text   Zotero

Fully coupled numerical models for simulating mine backfill typically assume zero pore pressure conditions at the top of the fill. This implies full saturation of the fill mass. In this paper, Gibson's solution is examined to identify situations where this use of zero pore pressure boundary conditions is likely to be unrealistic. A model that is able to capture phreatic draw down and fill desaturation is then briefly described. The model also accounts for changes in strength, stiffness and permeability due to cement hydration. An example two−dimensional simulation of stope backfilling is then presented. The analysis is conducted assuming full saturation and zero pore pressure boundary conditions, as well as a more realistic simulation that accounts for desaturation. It is shown that phreatic draw down and fill desaturation have a significant impact on pore pressure within the fill mass and barricade loads.

Biot, MA 1941, ‘General theory of three-dimensional consolidation’, Journal of Applied Physics, vol. 12, pp. 155-164.
Doherty, JP 2013a, ‘A model for cemented backfill incorporating chemical volume strains: I. Development of a constitutive model’, Canadian Geotechnical Journal, in review.
Doherty, JP 2013b, ‘A model for cemented backfills incorporating chemical volume strains: II. Application’, submitted to Canadian Geotechnical Journal.
Fahey, M, Helinski, M & Fourie, AB 2010, ‘Consolidation in accreting sediments: Gibson’s solution applied to backfilling of mine stopes’, Géotechnique, vol. 60, no. 11, pp. 877-82.
Fredlund, D & Xing, A 1994, ‘Equations for the soil-water characteristic curve’, Canadian Geotechnical Journal, vol. 31, no. 6, pp. 521-32.
Gibson, RE 1958, ‘The progress of consolidation of a clay layer increasing in thickness with time’, Géotechnique, vol. 8, no. 4, pp. 171-82.
Hasan, A, Suazo, G & Fourie, AB 2013, ‘Full scale experiments on the effectiveness of a drainage system for cemented paste backfill’, RJ Jewell, AB Fourie, J Caldwell & J Pimenta (eds), Proceedings of the 16th International Seminar on Paste and Thickened Tailings, Australian Centre for Geomechanics, Perth, pp. 379-92.
Helinski, M 2008, ‘The mechanics of mine backfill’, PhD thesis, The University of Western Australia.
Helinski, M, Fahey, M & Fourie, AB 2011, ‘Behavior of cemented paste backfill in two mine stopes: Measurements and modeling’, Journal of Geotechnical and Geoenvironmental Engineering, vol. 137, no. 2, pp. 171-82.
Li, L & Aubertin, M 2009, ‘Influence of water pressure on the stress state in stopes’, Geotechnical and Geological Engineering, vol. 27, no. 1, pp. 1-11.
Thompson, BD, Bawden, WF & Grabinsky, MW 2011, ‘In situ measurements of cemented paste backfill at the Cayeli Mine’, Canadian Geotechnical Journal, vol. 49, no. 7, pp. 755-72.

© Copyright 2023, Australian Centre for Geomechanics (ACG), The University of Western Australia. All rights reserved.
View copyright/legal information
Please direct any queries or error reports to