Effect of fault-slip source mechanism on seismic source parameters
Tóm tắt
Fault-slip bursts in underground mines could cause devastating damage to mine openings. In the present study, three types of underlying mechanisms that could trigger fault-slip are examined, namely asperity shear, stope extraction, and a combination thereof, with numerical analysis. First, a numerical model is constructed, in which a fault running parallel to a steeply dipping, tabular orebody is modeled. Static analysis is then performed, whereby stopes in the orebody are extracted. Based on the stress state obtained from the analysis, dynamic analyses are carried out to simulate fault-slip, using different simulation techniques representing the mechanisms of fault-slip. The results show that when fault-slip is induced by asperity shear, slips could spread over an extensive area of the fault. In contrast, the fault-slip area is limited to the vicinity of an extracted stope when fault-slip is caused by stope extraction. The results further indicate that asperity shear could induce strike-slip faulting. It is revealed that when fault-slip is caused by the combination, the magnitude of fault-slip significantly increases. Investigation of the slip rate shows that fault-slip induced by stope extraction induces slightly higher slip rates than that caused by asperity shear. It is also found that fault-slip induced by stope extraction ruptures faster along the fault than that induced by asperity shear. Lastly, the effect of the mining rate on the magnitude of fault-slip is examined. The result indicates that stope extraction with a low mining rate can considerably decrease the cumulative seismic moment of fault-slip that takes place during the mining sequence.
Tài liệu tham khảo
Aki K, Richards RG (1980) Quantitative seismology: theory and method. Freeman, San Francisco
Alber M, Fritschen R (2011) Rock mechanical analysis of a M1 = 4.0 seismic event induced by mining in the Saar District. Ger Geophys J Int 186:359–372
Alber M, Fritschen R, Bischoff M, Meier T (2009) Rock mechanical investigations of seismic events in a deep longwall coal mine. Int J Rock Mech Min Sci 46:408–420
Arjang B, Herget G (1997) In situ ground stresses in the Canadian hardrock mines: an update. Int J Rock Mech Min 34
Barton N (1973) Review of a new shear-strength criterion for rock joints. Eng Geol 7:287–332
Barton N, Choubey V (1977) The shear strength of rock joints in theory and practice. Rock Mech 10:1–54
Blake W, Hedley DGF (2003) Rockbursts case studies from North America hard-rock mines. Society for Mining, Metallurgy, and Exploration, Littleton
Diederichs MS (1999) Instability of hard rockmass: the role of tensile damage and relaxation University of Waterloo
Domański B, Gibowicz SJ (2008) Comparison of source parameters estimated in the frequency and time domains for seismic events at the Rudna copper mine. Pol Acta Geophys 56:324–343
Henning J (1998) Ground control strategies at the bousquet 2 mine. McGill University
Hofmann GF, Scheepers LJ (2011) Simulating fault slip areas of mining induced seismic tremors using static boundary element numerical modelling. Min Technol 120:53–64
Itasca (2009) FLAC3D—fast Lagrangian analysis of continua, 4.0 edn. Itasca Consulting Group Inc. U.S.A.
Kanamori H (2001) Energy budget of earthquakes and seismic efficiency. In: Earthquake thermodynamics and phase transformations in the earth’s interior. Academic Press, pp 293–305
Malek F, Suorineni FT, Vasak P Geomechanics strategies for rockburst management at Vale Inco Creighton Mine. In: Diederichs M, Grasselli G (eds) ROCKENG09, Toronto, 2009
McGarr A (1991) Observations constraining near-source ground motion estimated from locally recorded seismograms. J Geophys Res 96:495–508
McGarr A (1994) Some comparisons between mining-induced and laboratory earthquakes PAGEOPH 142:467–489
McGarr A (2002) Control of strong ground motion of mining-induced earthquakes by the strength of the seismogenic rock mass. J S Afr Inst Min Metall:225–229
McGarr A, Fletcher JB (2001) A method for mapping apparent stress and energy radiation applied to the 1994 Northridge earthquake fault zone—revisited. Geophys Res Lett 28:3529–3532
Mitri HS, Tang B, Simon R (1999) FE modelling of mining-induced energy release and storage rates. J S Afr Inst Min Metall 99:103–110
Ortlepp WD (2000) Observation of mining-induced faults in an intact rock mass at depth. Int J Rock Mech Min Sci 37:423–426
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 119:175–181
Ryder JA (1988) Excess shear stress in the assessment of geologically hazardous situations. J S Afr Inst Min Metall 88:27–39
Sainoki A, Mitri HS (2014a) Dynamic behaviour of mining-induced fault slip. Int J Rock Mech Min Sci 66c:19–29
Sainoki A, Mitri HS (2014b) Dynamic modelling of fault slip with Barton’s shear strength model. Int J Rock Mech Min Sci 67:155–163. doi:10.1016/j.ijrmms.2013.12.023
Sainoki A, Mitri HS (2014c) Methodology for the interpretation 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 (2014d) Numerical simulation of rock mass vibrations induced by nearby production blast. Can Geotech J. doi:10.1139/cgj-2013-0480
Sainoki A, Mitri HS (2014e) Simulating intense shock pulses due to asperities during fault-slip. J Appl Geophys 103:71–81
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 121:226–235
White BG, Whyatt JK (1999) Role of fault slip on mechanisms of rock burst damage, Lucky Friday Mine, Idaho, USA. Paper presented at the 2nd Southern African Rock Engineering Symposium. Implementing Rock Engineering Knowledge, Johannesburg, S. Africa
Zhang Y, Mitri H (2008) Elastoplastic stability analysis of mine haulage drift in the vicinity of mined stopes. Int J Rock Mech Min Sci 45:574–593