Stacey, TR, Ndlovu, X & Ortlepp, WD 2007, 'Dynamic Rock Failures Due to "High" Stress at Shallow Depths', in Y Potvin (ed.), Proceedings of the Fourth International Seminar on Deep and High Stress Mining
, Australian Centre for Geomechanics, Perth, pp. 193-204, https://doi.org/10.36487/ACG_repo/711_13
High stresses are expected in deep mines, and it is perhaps unusual for rock failure due to high stresses to be
observed in shallow mining. In this paper, stress-induced failures of competent rock are described in three
shallow mining situations. Two of the rock failures occurred with considerable violence, both involving
significant strain bursting seismicity. Rock failures in the third case often occurred with some violence and
were preceded by audible noises. The first situation is failure of very competent granite in a dimension stone
quarry, in which the depth of the “vertical cut slope” was about 3 m. The second situation is failure of the
roof in a coal mine at a depth of about 50 m below surface. The third situation is also failure of the roof in a
coal mine, but at a depth of about 25 m below surface. None of these failures can be explained using
commonly-used rock strength criteria.
Dunner, C., Bigarre, P., Clement, C., Merrien-Soukatchoff, V. and Gunzberger, Y. (2007) Natural and
thermomechanical stress field measurements at the “Rochers de Valabres” Pilot Site Laboratory in France.
Proceediongs 11th Int. Cong. Int. Soc. Rock Mech., Lisbon, Taylor and Francis Group, Vol. 1, pp. 69-72.
Frith, R.C., Thomas, R., Hill, D. and Buddery, P. (2002) Final Project Report – Survey of horizontal stresses in coal
mines from available measurements and mapping. SIMRAC Project COL 802, 51 p.
Martin, C.D. (1990) Characterising in situ domains at the AECL Underground Research Laboratory. Can. Geotech.
Journal No. 27, pp. 631-646.
Martin, C.D. (1997) 17th Canadian Geotechnical Colloquium: The effect of cohesion loss and stress path on brittle rock
strength. Can. Geotech. Journal, No. 34. Vol. 5, pp. 698-725.
Martin, C.D., Kaiser, P.K. and McCreath, D.R. (1998) Hoek – Brown parameters for predicting the depth of brittle
failure around tunnels. Can. Geotech. Journal, No. 36, pp. 136-151.
Martin, C.D., Read, R.S. and Martino, J.B. (1997) Observation of brittle failure around a circular test tunnel. Int. J.
Rock Mech. Min. Sci. and Geomech. Abstr., Vol. 34(7), pp. 1065-1073.
Rock Behaviour Under High Stress
Deep Mining 07, Perth, Australia 203
Martino, J.B. and Chandler, N.A. (2004) Excavation-induced damage studies at the Underground Research Laboratory.
Int. J. Rock Mech. and Min. Sci., Vol. 41, pp. 1413-1426.
MHSC 2004/2005 Annual Report (2005) INTERNET.
Cited 10 June 2006.
Munsamy, L. (2003) Determination of the high horizontal stresses at Nooitgedacht Colliery and strategies to overcome
the roof instability. MINN594 Investigational Project, School of Mining Engineering, University of the
Witwatersrand, 76 p.
Ndlovu, X. (2006) Three dimensional analyses of stress and strain distributions around bord and pillar geometries, MSc
Dissertation, University of the Witwatersrand, 171 p.
Ndlovu, X. and Stacey, T.R. (2005) Observations of roof guttering in a coal mine. Proceedings 3rd Southern African
Rock Engng Symp. Best Practices in rock engineering, Randburg, S. Afr. Inst. Min. Metall., Symposium Series
S41, pp. 285-300.
Ndlovu, X. and Stacey, T.R. (2007) Observations and analyses of roof guttering in a coal mine. Jl S. Afr. Inst. Min. Metall.,
Vol. 107, No. 8, pp. 477-492.
Ortlepp, W.D. and Moore, M.A. (1987) Underground observation of high propagation-rate extension fractures. Proc. 6th
Int. Cong. Int. Soc. Rock Mech., Montreal, A.A.Balkema, Vol. 2, pp. 1173-1180.
Stacey, T.R. (1981) A simple extension strain criterion for fracture of brittle rock. Int. J. Rock Mech. Min. Sci., Vol. 18,
van der Merwe, J.N. and Madden, B.J. (2002) Rock Engineering for Underground Coal Mining. S. Afr. Inst. Min.
Metall., Special Publications Series 7.
Walker, G. and Altounyan, P. (2001) In situ stress measurements at Nooitgedacht, No. 5 Seam Section 50/51. Rock
Mechanics Technology (Pty) Ltd Report to Greenside Colliery, AngloCoal, 14 p.
Dynamic Rock Failures Due to “High” Stress at Shallow Depth T.R. Stacey, et al.
204 Deep Mining 07, Perth, Australia