Effect of pore pressure on deformation and unstable snap-back for shear band and elastic rock system

  • Wang Xue-bin  (王学滨)Email author


Fast Lagrangian analysis of continua(FLAC) was used to study the influence of pore pressure on the mechanical behavior of rock specimen in plane strain direct shear, the distribution of yielded elements, the distribution of displacement and velocity across shear band as well as the snap-back (elastic rebound) instability. The effective stress law was used to represent the weakening of rock containing pore fluid under pressure. Numerical results show that rock specimen becomes soft (lower strength and hardening modulus) as pore pressure increases, leading to higher displacement skip across shear band. Higher pore pressure results in larger area of plastic zone, higher concentration of shear strain, more apparent precursor to snap-back (unstable failure) and slower snap-back. For higher pore pressure, the formation of shear band-elastic body system and the snap-back are earlier; the distance of snap-back decreases; the capacity of snap-back decreases, leading to lower elastic strain energy liberated beyond the instability and lower earthquake or rockburst magnitude. In the process of snap-back, the velocity skip across shear band is lower for rock specimen at higher pore pressure, showing the slower velocity of snap-back.

Key words

pore pressure shear band snap-back strain-softening unstable failure stress-strain curve 


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  1. [1]
    NICHOLSON C, WESSON R L. Triggered earthquakes and deep-well activities[J]. Pure and Applied Geophysics, 1992, 139(3/4): 561–578.CrossRefGoogle Scholar
  2. [2]
    BISCONTIN G, PESTANA J M, NADIM F. Seismic triggering of submarine slides in soft cohesive soil deposits[J]. Marine Geology, 2004, 203(3/4): 341–354.CrossRefGoogle Scholar
  3. [3]
    WANG Xue-bin, YANG Xiao-bin, ZHANG Zhi-hui, et al. Dynamic analysis of fault rockburst based on gradient-dependent plasticity and energy criterion[J]. J Univ Sci Technol Beijing, 2004, 11(1): 5–9.Google Scholar
  4. [4]
    WANG Xue-bin, DAI Shu-hong, HAI Long. Quantitative calculation of dissipated energy of fault rock burst based on gradient-dependent plasticity[J]. J Univ Sci Tech Beijing, 2004, 11(3): 197–201.Google Scholar
  5. [5]
    WANG Xue-bin, PAN Yi-shan, HAI Long. Instability criterion of fault rock burst based on gradient-dependent plasticity[J]. Chinese Journal of Rock Mechanics and Engineering, 2004, 23(4): 588–591. (in Chinese)Google Scholar
  6. [6]
    WANG Xue-bin, HUANG Mei, ZHAO Yang-feng, et al. Analysis on relation between snap-back of specimen and snap-back of system composed of direct shear testing machine and specimen[J]. Chinese Journal of Rock Mechanics and Engineering, 2004, 23(3): 379–382. (in Chinese)Google Scholar
  7. [7]
    WANG Xue-bin, SONG Wei-yuan, HUANG Mei, et al. Analysis on fault rockburst considering effects of water weakening and strain gradient[J]. Chinese Journal of Rock Mechanics and Engineering, 2004, 23(11): 1815–1818. (in Chinese)Google Scholar
  8. [8]
    WANG Xue-bin. Strain localization of rock failure and instability criterion of rockburst[C]// WANG Ya-jun et al, ed. Progress in Safety Science and Technology. Beijing: Science Press, 2004, IV: 244–249.Google Scholar
  9. [9]
    WANG Xue-bin. Shear stress distribution and characteristics of deformation for shear band-elastic body system at pre-peak and post-peak[J]. J Cent South Univ Technol, 2005, 12(5): 611–617.CrossRefGoogle Scholar
  10. [10]
    WANG Xue-bin. Numerical simulation of influence of loading rate on deformation characteristics and snap-back for fault band and elastic rock system[J]. Rock and Soil Mechanics, 2006, 27(2): 242–247. (in Chinese)Google Scholar
  11. [11]
    WANG Xue-bin. Numerical simulation of influence of shear dilatancy on deformation characteristics of shear band-elastic body system[J]. J Coal Sci Engng, 2004, 10(2): 1–6. (in Chinese)Google Scholar
  12. [12]
    WANG Xue-bin, PAN Yi-shan, DING Xiu-li, et al. Study on effect of pore pressure on strain localization of rock and numerical simulation[J]. Journal of Geomechanics, 2001, 7(2):139–143. (in Chinese)Google Scholar
  13. [13]
    TANG Chun-an, FU Yu-fang, ZHAO Wen. A new approach to numerical simulation of source development of earthquake[J]. Acta Seismologica Sinica, 1997, 10(4): 425–434.CrossRefGoogle Scholar
  14. [14]
    LIN Peng, TANG Chun-an, CHEN Zhong-hui, et al. Numerical and experimental study of deformation and failure behavior in a double rock specimen system[J]. Earthquake, 1999, 19(4): 413–418. (in Chinese)Google Scholar
  15. [15]
    MAYER L, LU Z. Elastic rebound following the Kocaeli earthquake, Turkey, recorded using synthetic aperture radar interferometry[J]. Geology, 2001, 29(6): 495–498.CrossRefGoogle Scholar
  16. [16]
    JOHNSON A M, JOHNSON K M, DURDELLA J, et al. An emendation of elastic rebound theory: Main rupture and adjacent belt of right-lateral distortion detected by Viaduct at Kaynasli, Turkey 12 November 1999 Duzce Earthquake[J]. Journal of Seismology, 2002, 6(3): 329–346.CrossRefGoogle Scholar
  17. [17]
    YIN You-quan, DU Jing. A swallow-tail type catastrophic model of earthquake process [J]. Acta Seismological Sinica, 1994, 16(4): 521–528.CrossRefGoogle Scholar

Copyright information

© Published by: Central South University Press, Sole distributor outside Mainland China: Springer 2007

Authors and Affiliations

  1. 1.Department of Mechanics and Engineering SciencesLiaoning Technical UniversityFuxinChina

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