Abstract
The presence of geological faults intersecting with steeply dipping orebodies is not uncommon in hardrock mining. More often than not, such a scenario leads to seismic activities as ore extraction approaches the intersection point. This is particularly true for deep mining. This paper examines the influence of mining direction, i.e., overhand (bottom-up) versus underhand (top-down) mining, on the reactivation of a footwall fault in a sublevel stoping system. To do so, the static and dynamic behaviour of a footwall fault intersecting with a steeply dipping orebody is investigated. A model parametric study is undertaken with respect to the dip angle of the fault and the location of the fault intersection point with the orebody. The static analyses demonstrate that the volume of ore extracted before mining activity reaches the fault intersection is an influential factor, which impacts the degree of unclamping of the fault. It is thus suggested that mining directions be assessed in such a way as to minimize the volume of mined ore prior to intersection with the fault. It is also shown that the effect of mining direction on seismicity along the fault significantly decreases as the fault dip angle decreases. A dynamic analysis is then carried out and it confirms the same trends as the static analysis, i.e., fault-slip occurs over a larger fault surface area as the volume of extracted ore prior to intersecting the fault increases. However, there is no noticeable difference in the intensity of near-field ground motion during fault-slip for the two mining directions. A case study of the Lucky Friday Mine is then reviewed, where bedding faults intersect with a steeply dipping vein from the footwall side. It is reported that shear movements and seismicity on the fault are not the direct cause of rockbursts that took place around a stope. Rather, the damage was caused by the stress change induced by the slip. In order to elucidate the mechanism, the development of deviatoric stress induced by the shear movement along the footwall fault is analyzed while comparing with the case at Lucky Friday Mine. In order to clarify the influence of shear movements, the deviatoric stress is compared in models with and without faults. It is shown that the shear movement significantly contributes to the increase in deviatoric stress around the fault, thus suggesting damage to the rockmass and generation of seismically active zones. The results are found to be in agreement with the case at Lucky Friday Mine.
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References
ABAQUS (2003) ABAQUS online documentation: Ver 6.4–1. Dassault Systemes, France
Alber M, Fritschen R (2011) Rock mechanical analysis of a M1 = 4.0 seismic event induced by mining in the Saar District, Germany. Geophys J Int 186:359–372
Arjang B, Herget G (1997) In situ ground stresses in the Canadian Hardrock Mines: an update. Int J Rock Mech Min Sci Geomech Abstr 34
Barton N, Choubey V (1977) The shear strength of rock joints in theory and practice. Rock Mech 10:1–54
Bieniawski ZT (1976) Rock mass classification in rock engineering. In In Exploration for rock engineering. Balkema, Cape Town
Blake W, Hedley DGF (2003) Rockbursts case studies from North America Hard-Rock Mines. Society for Mining, Metallurgy, and Exploration, Littleton, Colorado, USA
Brinkmann JR (1987) Separating shock wave and gas expansion breakage mechanism. In 2nd International Symposium on Rock Fragmentation by Blasting. p 6–15
Cappa F, Rutqvist J (2011) Modeling of coupled deformation and permeability evolution during fault reactivation induced by deep underground injection of CO2. International Journal of Greenhouse Gas Control 5:336–346
Castro LAM, Bewick RP, Carter TG (2012) An overview of numerical modelling applied to deep mining. Innovative Numerical Modelling in Geomechanics: 393–414
Diederichs MS (1999) Instability of hard rockmass: the role of tensile damage and relaxation University of Waterloo. Waterloo, Canada
Dirige APE, McNearny RL, Thompson DS (2009) The effect of stope inclination and wall rock roughness on backfill free surface stability. In: Diederichs M, Grasselli G (eds) The 3rd CANUS Rock Mechanics Symposium, Toronto, Canada
Domański B, Gibowicz SJ (2008) Comparison of source parameters estimated in the frequency and time domains for seismic events at the Rudna copper mine, Poland. Acta Geophysica 56(2):324–343
Gertsch RE, Bullock RL (1998) Techniques in underground mining: selections from underground mining method handbook. Society for Mining, Metallurgy, and Exploration (SME)
Hartman HL (1992) SME Mining Engineering Handbook. Society for Mining, Metallurgy, and Exploration, Inc. (SME), Denver
Hedley DGF (1992) Rockburst handbook for ontario hard rock mines. Ontario Mining Association
Henning J (1998) Ground control strategies at the bousquet 2 mine. In: Mining & materials engineering. McGill University, Montreal, QC, Canada
Hoek E (2007) Practical rock engineering
Hoek E, Brown ET (1997) Practical estimates of rock mass strength. International Journal of Rock Mechanics and Mining Science 34(8):1165–1186
Hofmann GF, Scheepers LJ (2011) Simulating fault slip areas of mining induced seismic tremors using static boundary element numerical modelling. Min Technol 120(1):53–64
Itasca (2009) FLAC3D—fast Lagrangian analysis of continua. Itasca Consulting Group Inc, U.S.A.
Itasca Consulting Group, I (2013) Kubrix Ver. 12. Itasca, Minneapolis
Lysmer J, Kuhlemeyer RL (1969) Finite dynamic model for infinite media. J Eng Mech 95(EM4):859–877
Marinos P, Hoek E (2001) Estimating the geotechnical properties of heterogeneous rock masses such as Flysch. Bull Eng Geol Environ 60:85–92
McGarr A (1991) Observations constraining near-source ground motion estimated from lacally recorded seismograms. J Geophys Res 96(B10):16495–16508
McGarr A (1999) On relating apparent stress to the stress causing earthquake fault slip. J Geophys Res 104(B2):3003–3011
McGarr A (2002) Control of strong ground motion of minig-induced earthquakes by the strength of the seismogenic rock mass. J South Afr Inst Min Metall 225–229
McNeel R, Associates (2015) Rhinoceros 3D
Michael JF, Dorman KR (1984) Information Circular-United States, Bureau of Mines; − IC no. 8973: underhand cut and fill for rock burst control. US Bureau of Mines
Mitri HS, Tang B, Simon R (1999) FE modelling of mining-induced energy release and storage rates. Journal South African Institute of Mining and Metallurgy 99(2):103–110
Ortlepp WD (2001) The behaviour of tunnels at great depth under large static and dynamic pressures. Tunn Undergr Space Technol 16:41–48
Potvin Y, Jarufe J, Wesseloo J (2010) Interpretation of seismic data and numerical modelling of fault reactivation at el Teniente, Reservas Norte sector. Min Technol 119(3):175–181
Ryder JA (1988) Excess shear stress in the assessment of geologically hazardous situations. Journal of South African Institute of Mining and Metallurgy 88(1):27–39
Sainoki A, Mitri HS (2014a) Dynamic behaviour of minig-induced fault slip. International Journal of Rock Mechanics and Mining Science 66c:19–29
Sainoki A, Mitri HS (2014b) Dynamic modelling of fault slip with Barton’s shear strength model. International Journal of Rock Mechanics and Mining Science 67:155–163. doi:10.1016/j.ijrmms.2013.12.023
Sainoki A, Mitri HS (2014c) Evaluation of fault-slip potential due to shearing of fault asperities. Canadian Geotechnial Journal 52(10):1417–1425
Sainoki A, Mitri HS (2014d) Methodology for the interpretaiton of fault-slip seismicity in a weak shear zone. J Appl Geophys 110:126–134. doi:10.1016/j.jappgeo.2014.09.007
Sainoki A, Mitri HS (2015) Effect of slip-weakening distance on selected seismic source parameters of mining-induced fault-slip. International Journal of Rock Mechanics and Mining Science 73:115–122. doi:10.1016/j.ijrmms.2014.09.019
Sjöberg J, Perman F, Quinteiro C, Malmgren L, Dahner-Lindkvist C, Boskovic M (2012) Numerical analysis of alternative mining sequences to minimize potential for fault slip rockbursting. Min Technol 121(4):226–235
Tesarik DR, Seymour JB, Yanske TR (2003) Post-failure behaviour of two mine pillars confined with backfill. International Journal of Rock Mechanics and Mining Science 40(2):221
White BG, Whyatt JK (1999) Role of fault slip on mechanisms of rock burst damage, Lucky Friday Mine, Idaho, USA. In: 2nd Southern African Rock Engineering Symposium. Implementing Rock Engineering Knowledge, Johannesburg, S. Africa
Williams TJ, Bayer DC, Bren MJ, Pakalnis RT, Marjerison JA, Langston RB (2007) Underhand cut and fill mining as practiced in three cdeep hard rock mines in the United States. In: CIM conference exhibition, Montrea, Canada
Yuana F, Prakash V (2008) Use of a modified torsional Kolsky bar to study frictional slip resistance in rock-analog materials at coseismic slip rates. Int J Solids Struct 45:4247–4263
Zhang Y, Mitri H (2008) Elastoplastic stability analysis of mine haulage drift in the vicinity of mined stopes. International Journal of Rock Mechanics and Mining Science 45:574–593
Acknowledgements
This work is financially supported by a grant by the Natural Science and Engineering Research Council of Canada (NSERC) in partnership with Vale Ltd—Sudbury Operations, Canada, under the Collaborative Research and Development Program. The authors are grateful for their support.
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Sainoki, A., Mitri, H.S. Influence of mining activities on the reactivation of a footwall fault. Arab J Geosci 10, 99 (2017). https://doi.org/10.1007/s12517-017-2913-4
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DOI: https://doi.org/10.1007/s12517-017-2913-4