Estimation of in situ stress from borehole breakout for improved understanding of excavation overbreak in brittle-anisotropic rock

Authors: LeRiche, A; Kalenchuk, KS; Diederichs, MS

Open access courtesy of:

DOI https://doi.org/10.36487/ACG_rep/1704_13_LeRiche

Cite As:
LeRiche, A, Kalenchuk, KS & Diederichs, MS 2017, 'Estimation of in situ stress from borehole breakout for improved understanding of excavation overbreak in brittle-anisotropic rock', in J Wesseloo (ed.), Deep Mining 2017: Proceedings of the Eighth International Conference on Deep and High Stress Mining, Australian Centre for Geomechanics, Perth, pp. 209-222, https://doi.org/10.36487/ACG_rep/1704_13_LeRiche

Download citation as:   ris   bibtex   endnote   text   Zotero


Abstract:
During deep tunnelling or mining infrastructure development, the assumed stress state has significant implications on geomechanical design. Remote measurement of the three-dimensional stress state at depth has proven to be a significant challenge and is often assumed from historic tests or the regional tectonic setting. To date, borehole breakout analysis has only provided some assistance for orientation of the principal stresses in the plane perpendicular to the borehole axis. This paper presents a stress estimation methodology using numerical modelling, which allows for the back analysis of breakout profiles from a shaft pilot hole at KGHM’s Victoria project in Sudbury, Canada. By iteratively changing the horizontal principal stress ratio and maximum tangential wall stress, a set of generalised curves relating breakout characteristics (breakout depth and opening angle) and borehole strength along the 2 km borehole were made. By recording the change in breakout geometry along the length of the hole, the curves can be used to gain an understanding of changes in stress state as a function of depth and lithology. Given the foliated nature of the units intersected throughout the borehole, the effects of systematically oriented structure on breakout was assessed. This provides a relative understanding of how such structure may cause an overestimation of stress from the back analysis of breakout. With the choice of an appropriate constitutive model, characterisation of the full stress tensor through back analysis of borehole scale failure was made with a greater degree of confidence.

Keywords: borehole breakout, effective borehole strength, in situ stress, acoustic televiewer (ATV), excavation overbreak, brittle rock mass modelling

References:
Barton, CA, Zoback, MD & Burns, KL 1988, ‘In situ stress orientation and magnitude at the Fenton Geothermal Site, New Mexico, determined from wellbore breakouts’, Geophysical Research Letters, vol. 15, no. 5, pp. 467–470.
Cowan, EJ, Riller, U & Schwerdtner, WM 1999, ‘Emplacement geometry of the Sudbury igneous complex: Structural examination of a proposed impact melt-sheet’, in B Dressler & V Sharpton (eds), Large Meteorite Impacts and Planetary Evolution II, Geological Society of America, Boulder, Colorado.
Diederichs, MS 1999, ‘Instability of hard rockmasses: The role of tensile damage and relaxation’, PhD thesis, The University of Waterloo, Waterloo, Ontario.
Diederichs, MS 2003, ‘Rock fracture and collapse under low confinement conditions’, Rock Mechanics and Rock Engineering, vol. 36, no. 5, pp. 339–381.
Diederichs, MS 2007, ‘The 2003 geotechnical colloquium: Mechanistic interpretation and practical application of damage and spalling prediction criteria for deep tunnelling’, Canadian Geotechnical Journal, vol. 44, no. 1, pp. 82–116.
Duan, K & Kwok, CY 2015, ‘Evolution of stress-induced borehole breakout in inherently anisotropic rock: Insights from discrete element modeling’, Journal of Geophysical Research: Solid Earth, vol. 121, no. 1, pp. 2361–2381.
Haimson, B 2006, ‘Micromechanisms of borehole instability leading to breakouts in rocks’, International Journal of Rock Mechanics & Mining Sciences, vol. 44, pp. 157–173.
Hajiabdolmajid, V, Kaiser, PK & Martin, CD 2002, ‘Modelling brittle failure of rock’, International Journal of Rock Mechanics and Mining Sciences, vol. 39, no. 6, pp. 731–741.
Herget, G 1987, ‘Technical note: Stress assumptions for underground excavations in the Canadian Shield’, International Journal of Rock Mechanics and Mining Sciences, vol. 24, no. 1, pp. 95–97.
Kirsch, G 1898, ‘Die Theorie der Elastizitat und die Bedurfnisse der Festigkeitslehre’, Zantralblatt Verlin Deutscher Ingenieure, vol. 42, pp. 797–807.
Martin, CD 1997, ‘Seventeenth Canadian geotechnical colloquium: The effect of cohesion loss and stress path on brittle rock strength’, Canadian Geotechnical Journal, vol. 34, pp. 698–725.
Meier, T, Rybacki, E, Backers, T & Dresen, G 2015,’Influence of bedding angle on borehole stability: A laboratory investigation of transverse isotropic oil shale’, Rock Mechanics and Rock Engineering, vol. 48, no. 1, pp. 1535–1546.
Mercier-Langevin, F & Hadjigeorgiou, J 2011, ‘Towards a better understanding of squeezing potential in hard rock mines’, Transactions of the Institution of Mining and Metallurgy, Section A: Mining Technology, vol. 120, no. 1, pp. 36–44.
MDEng (Mine Design Engineering) 2015, MDEng final report #0308-R1412-D01 Victoria Project integrated engineering study, KGHM International, Sudbury, Ontario.
Quadra FNX Mining LTD. 2011, NI 43-101: Technical report on the Victoria Project Deposit, Sudbury, Ontario, Canada, Victoria Deposit, Sudbury.
Riller, U 2005, ‘Structural Characteristics of the Sudbury impact structure, Canada: Impact-induced versus orogenic deformation-A review’, Meteoritics & Planetary Science, vol. 40, no. 11, pp. 1723–1740.
Rocscience, Inc. 2016 RS2, version 9.0, Rocscience, Inc., Toronto, Ontario, viewed 19 January 2017,
Santimano, T & Riller, U 2012, ’Revisiting thrusting, reverse faulting and transpression in the southern Sudbury Basin, Ontario’, Precambrian Research, vol. 200–203, pp. 74–81.
Snelling, PE, Laurent, G & McKinnon, SD 2012, ‘The role of geologic structure and stress in triggering remote seismicity in Creighton Mine, Sudbury, Canada’, International Journal of Rock Mechanics & Mining Sciences, vol. 58, pp. 166–179.
Trifu, CI & Suorineni, FT 2009, ‘Use of microseismic monitoring for rockburst management at Vale Inco mines’, in C Tang (ed.), Proceedings of the 7th International Symposium on Rockburst and Seismicity in Mines, Rinton Press, New York,
pp. 1105–1114.
Vernik, L & Zoback, MD 1992, ‘Estimation of maximum horizontal principal stress magnitude from stress-induced well bore breakouts in the Cajon Pass scientific research borehole’, Journal of Geophysical Research, vol. 97, no. B4, pp. 5109–5119.
Walton, G & Diederichs, MS 2015, ‘A mine shaft case study on the accurate prediction of yield and displacements in stressed ground using lab-derived material properties’, Tunnel and Underground Space Technology, vol. 49, pp. 98–113.
Walton, G, Diederichs, MS, Hume, C & Kalenchuk, K 2015a, ‘Borehole breakout analysis to determine the in situ stress state in hard rock’, Proceedings of the Forty-ninth US Rock Mechanics/Geomechanics Symposium, American Rock Mechanics Association, Alexandria, Virginia, pp. 287–304.
Walton, G, Diederichs, MS & Punkkinen, A 2015b, ‘The influence of constitutive model selection on predicted stresses and yield in deep mine pillars — A case study at the Creighton mine, Sudbury, Canada’, Geomechanics and Tunnelling, vol. 8, no. 5, pp. 441–449.
Zhang, J 2013, ‘Borehole stability analysis accounting for anisotropies in drilling to weak bedding planes’, International Journal of Rock Mechanics & Mining Sciences, vol. 60, pp. 160–170.
Zoback, ML 1992, ‘First- and second-order patterns of stress in the lithosphere: The world stress map project’, Journal of Geophysical Research, vol. 97, no. B8, pp. 703–728.
Zoback, MD, Moos, D & Mastin, L 1985, ‘Well bore breakouts and in situ stress’, Journal of Geophysical Research, vol. 90,
pp. 5523–5530.




© Copyright 2024, 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 repository-acg@uwa.edu.au