Paradoxical Features of Primary Shear Fractures and General Faults
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Authors: Tarasov, BG; Randolph, MF |
DOI https://doi.org/10.36487/ACG_repo/711_Tarasov
Cite As:
Tarasov, BG & Randolph, MF 2007, 'Paradoxical Features of Primary Shear Fractures and General Faults', in Y Potvin (ed.), Deep Mining 2007: Proceedings of the Fourth International Seminar on Deep and High Stress Mining, Australian Centre for Geomechanics, Perth, pp. 165-182, https://doi.org/10.36487/ACG_repo/711_Tarasov
Abstract:
This paper shows that hard rocks exhibit specific properties at high confining pressure that distinguish them markedly from common rock behaviour: they become extremely brittle and lose shear resistance within a certain range of shear rupture displacement. The combination of these two features results in increasing instability with depth and makes rupture abnormally violent, both of which are well established experimentally from studies of earthquakes and rock bursts at high stress levels. The behaviour is caused by the intrinsic nature of the fault structure, which is an echelon of blocks operating as hinges, essentially eliminating friction at high confining pressure of a certain displacement range. The paper demonstrates that, while the same structure may be found at different scale in primary fractures and general faults, significantly different mechanisms are responsible for the formation of the structure in each case. A new approach is proposed for understanding fault segmentation and the role of junctions in fault propagation. It is argued that segmentation is a result of advanced triggering of new fractures that propagate both towards the current fracture and in the opposite direction. This mechanism triples the fault propagation speed. Junctions formed at the meeting of the approaching segments help to accommodate the fault displacement and can significantly decrease the fault strength - thus contradicting the general belief that junctions represent strength barriers impeding the fault motion. The improved understanding of the fracture process is important for better prediction and mitigation of dynamic events such as earthquakes and rock bursts.
References:
Andrews, D. (1976) Rupture velocity of plane strain shear cracks. J. Geophys, Res. 81, pp. 5679-5687.
Andrews, D. (1980) A stochastic fault model, static case. J. Geophys. Res. 85, pp. 3867-3887.
Archuleta, R. (1982) Analysis of near source static and dynamic measurements from the 1979 Imperial Valley
earthquake. Bull. Seismol. Soc. Am., Vol. 72, pp. 1927-1956.
Ashby, M.F. and Sammis, C.G. (1990) The damage mechanics of brittle solids in compression, Pure Appl. Geophys.,
Vol. 133, pp. 489-521.
Ben-Zion, Y. and Andrews, D.J. (1998) Properties and implications of dynamic rupture along a material interface. Bull.
Seismol. Soc. Am., Vol. 88, pp. 1085-1094.
Broberg, K.B. (1999) Cracks and Fracture, London, Academic.
Burgmann, R., Pollard, D.D. and Martel, S.J. (1994) Slip distributions on faults: effects of stress gradients, inelastic
deformation, heterogeneous host-rock stiffness, and fault interaction, J. Struct. Geol. 16, pp. 1675-1690.
Chester, F.M., Evans, J.P. and Biegel, R.L. (1993) Internal structure and weakening mechanisms of the San Andreas
Fault, J. Geophys. Res., Vol. 98, pp. 771-786.
Clayton, L. (1966) Tectonic depressions along the Hase fault, a transcurrent fault in north Canterbury, New Zealand,
New Zealand J. Geol. Geophys. Vol. 9, pp. 94-104.
Das, S. (1985) Application of dynamic shear crack models to the study of the earthquake faulting process. Int. J. Fract.,
Vol. 27, pp. 263-276.
Domowska, R. and Rice, J.R. (1986) Continuum theories in solid earth physics, Amsterdam: Elsevier, pp.1881-1902.
Ellsworth, W.L. and Celebi, M. (1999) Near field displacement time histories of the M7.4 Kocaeli (Izmit) Turkey
earthquake of August 17, 1999. The American Geophysical Union Fall Meeting, Vol. 80 (Washington D.C:
American Geophysical Union), p. F648.
Freund, L.B. (1990) Dynamic fracture mechanics, Cambridge, Cambridge University Press.
Gao, H. (1993) Surface roughening and branching instabilities in dynamic fracture. J. Mech. Phys. Solids., Vol. 41, N3,
pp. 457-486.
Granier, T. (1985) Origin, damping and pattern of development of faults in granite, Tectonics, Vol. 4, pp. 721-737.
Hanks, T. and McGuire, R. (1981) The character of high-frequency strong ground motion. Bull. Seismol. Soc. Am.,
Vol. 71, pp. 2071-2095.
Harris, R.A. and Day, S.M. (1993) Dynamics of fault interaction: parallel strike-slip faults. J. Geophys. Res., Vol. 98,
pp. 4461-4472.
Harris, R.A. (1998) Introduction to special section: Stress triggers, stress shadows, and implications for seismic hazard.
J. Geophys. Res.-Solid Earth, Vol. 103, pp. 24347-24358.
Heaton, T.H. (1990) Evidence for and implications of self-healing pulses of slip in earthquake rupture. Physics of the
Earth and Planetary Interiors, Vol. 64, pp. 1-20.
Hernandez, B., Cotton, F. and Campillo, M. (1999) Contribution of Radar interferometry to a two-step inversion of the
kinematic process of the 1992 Landers earthquake. J. Geophys. Res. 104, pp. 13083-13099.
Hickman, S.H. (1991) Stress in the lithosphere and the strength of active faults, Rev. Geophys, Vol. 29, pp. 759-775.
Ida, Y. (1982) Stress concentration and unsteady propagation of longitudinal shear cracks, J. Geophys. Res., Vol. 77,
pp. 3796-3850.
Johnson, E. (1992) Process region changes for rapidly propagating cracks. Int. J. Fract., Vol. 55, pp. 47-63.
Kanamori, H. and Brodsky, E. (2001) The physics of earthquakes, Phys. Today, Vol. 54, pp. 34-40.
King, G.C.P and Sammis, C.G. (1992) The mechanisms of finite brittle strain, PAGEOPH, 138, pp. 611-639.
King, G.C.P. and Cocco, M. (2000) Fault interaction by elastic stress changes; new clues from earthquake sequences.
Advances in Geophys, Vol. 44, pp. 1-38.
Lockner, D.A., Byerlee, J.D., Kuksenko, V., Ponomarev, A. and Sidorin, A. (1991) Quasi-static fault growth and shear
fracture energy in granite Nature, Vol. 350, pp. 39 42.
Rock Behaviour Under High Stress
Deep Mining 07, Perth, Australia 181
Mandel, G. (2000) Faulting in brittle rocks. Springer-Verlag Berlin Heidelberg.
McKenzie, D. and Brune, N. (1972) Melting on fault planes during large earthquakes, Geophys. J. R. Astr. Soc.,
Vol. 29, pp. 65-78.
Moore, D.E., Summers, R. and Byerlee, J.D. (1990) Faults, fractures and other deformation features produced during
loading of granite in triaxial equipment. U.S. Geol. Surv. Open File Rep., pp. 90-349.
Moore, D.E. and Lockner, D.A. (1995) The role of microcracking in shear-fracture propagation in granite, J. Struct.
Geol. 17, pp. 95-114.
Nur, A. (1978) Nonuniform friction as a basis for earthquake mechanics. Pageoph, Vol. 116, pp. 964-989.
Olsen, K.B., Madariaga, R. and Archuleta, R.J. (1997) Three-dimensional dynamic simulation of the 1992 Landers
earthquake. Science, 278, 834.
Ortlepp, W.D. (1997) Rock fracture and rockbursts. The South African Institute of mining and metallurgy,
Johannesburg.
Ortlepp, W.D. (2000) Observation of mining-induced faults in an intact rock mass at depth. Int. J. Rock Mech. Min. Sc.,
Vol. 37, pp. 423-436.
Peng, S. and Johnson, A.M. (1972) Crack growth and faulting in cylindrical specimens of Chelmsford granite. Int. J.
Rock Mech. Min. Sci. Vol. 9, pp. 37-86.
Poliakov, A.N.B., Domowska, R. and Rice, J.R. (2002) Dynamic shear rupture interactions with fault bends and off-
axis secondary faulting, J. Geophys. Res. 107, No. B11, 2295, doi 10.1029/2001JB000572, ESE 6-1-6-18.
Ravi-Chandar, K. and Knauss, W.G. (1984) An experimentql investigation into dynamic fracture: I. Crack initiation and
arrest. Int. J. Fract., Vol. 25, pp. 247-262.
Reches, Z. and Lockner, D.A. (1994) Nucleation and growth of faults in brittle rocks. J. Geophys. Res. Vol. 99, No. B9,
pp. 18159-18173.
Rice, J.R. (2001) New perspectives on crack and fault dynamics in Mechanics for a New Millennium: The 20th
International congress of theoretical and applied mechanics, H. Aref and J.W. Phillips (eds), Dordrecht: Kluwer,
p. 23.
Rosakis, A.J., Samudrala, O. and Coker, D. (1999) Cracks faster than the shear wave speed. Science, Vol. 284,
pp. 1337-1340.
Rosakis, A.J. (2002) Intersonic shear cracks and fault ruptures. Advances in Physics, Vol. 51, No. 4, pp. 1189-1257.
Rosakis, A.J. (2006) Laboratory earthquakes. Int. J. Fracture, Vol. 138, pp. 211-218.
Scholz, C.H. (2002) The mechanics of earthquakes and faulting. Cambridge University Press.
Segall, P. and Pollard, D.D. (1980) The mechanics of discontinuous faults, J. Geophys. Res., Vol. 85, pp. 4337-4250.
Segall, P. and Pollard, D.D. (1983) Nucleation and growth of strike-slip faults in granite, J. Geoph. Res., Vol. 88,
pp. 555-68.
Sharp, R.V. and Clark, M.M. (1972) Geologic evidence of previous faulting near the 1968 rupture on the Coyote Creed
fault. U.S. Geol. Surv. Proof. Pap., Vol. 787, pp. 131-140.
Sibson, R.H. (1980) Power dissipation and stress levels on faults in the upper crust. J. Geophys. Res., Vol. 85, pp. 6239-
6247.
Sibson, R.H. (1985) Stopping of earthquake ruptures at dilatational jogs. Nature, 316, pp. 248-251.
Sibson, R.H. (1986) Rupture interaction with fault jogs, Earthquake source mechanisms, S. Das, J. Boatwright,
and C.H. Scholz (eds), American Geophysical Union, Washington.
Stain, R.S. (1999) The role of stress transfer in earthquake occurrence. Nature, Vol. 402, pp. 605-609.
Tarasov, B.G. (2007) Intersonic shear rupture mechanism (submitted to Int. J. Rock Mechanics 12.02.2007).
Tarasov, B.G. and Dyskin, A.V. (2005) The phenomenon of anomalous rock embrittlement. 6th International
Symposium on Rockburst and Seismicity in Mines Proceedings, Australia, pp. 311-317.
Tarasov, B.G. and Randolph, M.F. (2007) Frictionless shear at great depth and other paradoxes of hard rocks. Int. J.
Rock Mechanics (in press).
Tse, S. and Rice, J. (1986) Crustal earthquake instability in relation to the depth variation of frictional slip properties.
J. Geophys. Res. 91, pp. 9452-9472.
Vermilye, J.M. and Scholz, C.H. (1999) Fault propagation and segmentation: insight from the microstructural
examination of a small fault. J. Struct. Geol., Vol. 21, pp. 1623-1636.
Washabaugh, P.D., and Knauss, W.G. (1994) A reconciliation of dynamic crack velocity and Rayleigh wave speed in
isotropic brittle solids. Int. J. Fract., Vol. 65, pp. 97-114.
Weertman, J. (1980) Unstable slippage across a fault that separates elastic media of different elastic constants.
J. Geophys. Res., Vol. 85, p. 1455.
Wyss, M. and Brune, J. (1967) The Alaska earthquake of 28 March 1964: A complex multiple rupture. Bull. Seismol.
Soc. Am., Vol. 57, pp. 1017-1023.
Ziv, A. and Rubin, A.M. (2000) Static stress transfer and earthquake triggering: no lower threshold in sight, J. Geophys.
Res., 105, pp. 13631-13642.
Paradoxical Features of Primary Shear Fractures and General Faults B.G. Tarasov, M.F. Randolph
182 Deep Mining 07, Perth, Australia
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