Size effects on granite behavior under unloading rockburst test

Original Paper
First Online:
Received:
Accepted:

Abstract

Based on previous studies of rock behavior versus rock sample size and various research on rockburst simulation tests, a modified true-triaxial unloading testing machine was utilized to perform rockburst tests on granite specimens with changing heights for size effect investigation. The parameter of the height-to-thickness ratio (H/T) is proposed to characterize the rock scale, and it varies from 5 to 2 with a fixed thickness of 30 mm and changing heights from 150 to 60 mm. In this study, several testing methods were adopted to study the influence of H/T including non-destructive acoustic emission (AE) technology and high-speed camera recording systems as well as fragment kinetic energy analysis. The experimental results indicated that a size effect does exist during the rockburst simulation process and affects the rock failure strength and fracture mode. It can be seen that rock failure strength has an increasing trend with the decreasing of H/T. And at the higher H/T, extensile and splitting failures are dominant, and then the mixed failure mode including tensile and shear appears with decreasing H/T, until the single-plane shear becomes the main failure mode at the lowest H/T. AE energy release and kinetic energy of ejected fragments are not quite sensitive to sample size for H/T lower than 3. When the ratio of height and width is not lower than 3, the total AE energy during rock failure and kinetic energy of ejected fragments increased with the decreasing of sample size. With a further decrease of the ratio to 2, the total AE energy and kinetic energy of ejected fragments began to decrease.

Keywords

Size effect Height-to-thickness ratio Fracture mode Acoustic emission Fragment kinetic energy Unloading rockburst test 
This is a preview of subscription content, log in to check access.

Notes

Acknowledgments

The authors wish to thank the Key Project of National Natural Science Foundation of China (51134005). The work was also supported by the State Key Laboratory for GeoMechanics and Deep Underground Engineering, China University of Mining and Technology (no. SKLGDUEK1524). We would like to express our sincerest gratitude to the anonymous reviewers for their valuable modification suggestions that led to significant improvement of this article.

References

  1. Barton N, Lien R, Lunde J (1974) Engineering classification of rock masses for the design of tunnel support. Rock Mech Rock Eng 6(4):189–236CrossRefGoogle Scholar
  2. Bieniawski ZT (1968) The effect of specimen size on compressive strength of coal. Int J Rock Mech Min Sci Geomech Abstr 5(4):325–335CrossRefGoogle Scholar
  3. Brown ET (1974) Fracture of rock under uniform biaxial compression. In: Proceedings of the 3rd Congress of the International Society of Rock Mechanics, Denver, National Academy Science, Washington, DC, pp 111–117Google Scholar
  4. Cai M (2008) Influence of stress path on tunnel excavation response—numerical tool selection and modeling strategy. Tunn Undergr Space Technol 23:618–628CrossRefGoogle Scholar
  5. Cai M, Kaiser PK, Tasaka Y, Maejima T, Morioka H, Minami M (2004) Generalized crack initiation and crack damage stress thresholds of brittle rock masses near underground excavations. Int J Rock Mech Min Sci 41(5):833–847CrossRefGoogle Scholar
  6. Chen JT, Feng XT (2006) True triaxial experimental study on rock with high geostress. Chin J Rock Mech Eng 25(8):1537–1543 (In Chinese) Google Scholar
  7. Chen X, Xu Z (2016) The ultrasonic P-wave velocity-stress relationship of rocks and its application. Bull Eng Geol Environ 1–9. doi: 10.1007/s10064-016-0866-6
  8. Chen P, Zhou ZW (2012) Size effect experiment of rock material with RFPA2D. J Liaoning Tech Univ 31(6):842–845Google Scholar
  9. Cook NG (1965) A note on rockburst considered as a problem of stability. J S Afr Inst Min Met 65:437–446Google Scholar
  10. Fener M (2011) The effect of rock sample dimension on the P-wave velocity. J Nondestructive Eval 30(2):99–105CrossRefGoogle Scholar
  11. Girard L, Gruber S, Weber S, Beutel J (2013) Environmental controls of frost cracking revealed through in situ acoustic emission measurements in steep bedrock. Geophys Res Lett 40(9):1748–1753CrossRefGoogle Scholar
  12. He MC, Miao JL, LI DJ, Wang CG (2007) Experimental study on rockburst processes of granite specimen at great depth. Chin J Rock Mech Eng 26:865–876 (In Chinese) Google Scholar
  13. Hoek E, Brown ET (1980) Underground excavation in rock. The Institute of Mining and Metallurgy, London, pp 382–395Google Scholar
  14. Hudson JA, Crouch SL, Fairhurst C (1972) Soft, stiff and servo-controlled testing machines: a review with reference to rock failure. Eng Geol 6(3):155–189CrossRefGoogle Scholar
  15. Li G, Tang CA (2015) A statistical meso-damage mechanical method for modelling trans-scale progressive failure process of rock. Int J Rock Mech Min Sci 74:133–150CrossRefGoogle Scholar
  16. Li JL, Wang LH (2003) Study on size effect of unloaded rock mass. Chin J Rock Mech Eng 22(12):2032–2036 (In Chinese) Google Scholar
  17. Li WS, Huang SL et al (2012) Development of true triaxial experiment system for middle sized rock sample and its applications. Chin J Rock Mech Eng 31(11):2197–2203 (In Chinese) Google Scholar
  18. Li G, Liang ZZ, Tang CA (2015) Morphologic interpretation of rock failure mechanisms under uniaxial compression based on 3D multiscale high-resolution numerical modeling. Rock Mech Rock Eng 48:2235–2262CrossRefGoogle Scholar
  19. Moradian ZA, Ballivy G, Rivard P, Gravel C, Rousseau B (2010) Evaluating damage during shear tests of rock joints using acoustic emissions. Int J Rock Mech Min Sci 47(4):590–598CrossRefGoogle Scholar
  20. Nasseri MH, Goodfellow SD, Lombos L et al (2014) 3-D transport and acoustic properties of Fontainebleau sandstone during true-triaxial deformation experiments. Int J Rock Mech Min Sci 69:1–18Google Scholar
  21. Natau OP, Fröhlich BO, Amuschler TO (1983) Recent developments of the large-scale triaxial test. In: Proceedings of the fifth international congress of rock mechanics, Melbourne, pp 65–74Google Scholar
  22. Nicksiar M, Martin CD (2012) Evaluation of methods for determining crack initiation in compression tests on low-porosity rocks. Rock Mech Rock Eng 45(4):607–617CrossRefGoogle Scholar
  23. Pan PZ, Feng XT, Hudson JA (2009) Study of failure and scale effects in rocks under uniaxial compression using 3D cellular automata. Int J Rock Mech Min Sci 46(4):674–685CrossRefGoogle Scholar
  24. Pan ZJ, Ma Y, Connell LD et al (2015) Measuring anisotropic permeability using a cubic shale sample in a triaxial cell. J Nat Gas Sci Eng 26:336–344CrossRefGoogle Scholar
  25. Russenes BF (1974) Analyses of rockburst in tunnels in valley sides. Trondheim, Norwegian Institute of TechnologyGoogle Scholar
  26. Sagong M, Park D, Yoo J et al (2011) Experimental and numerical analyses of an opening in a jointed rock mass under biaxial compression. Int J Rock Mech Min Sci 48(7):1055–1067CrossRefGoogle Scholar
  27. Tao ZY (1987) Rockburst and its criterion in highly geostresses zone. Yangtze River 5(25):32Google Scholar
  28. Turchaninov IA (1981) Condition of extra-hard rock into weak rock under the influence of tectonic stresses of massifs. In Proc of International symposium on weak rock, Tokyo, 21–24, pp 555–559Google Scholar
  29. Wang JA, Park HD (2001) Comprehensive prediction of rockburst based on analysis of strain energy in rocks. Tunn Undergr Space Technol 16(1):49–57CrossRefGoogle Scholar
  30. Wong NY (2008) Crack coalescence in molded gypsum and Carrara marble. Massachusetts Institute of Technology, CambridgeGoogle Scholar
  31. Xu LS (2003) Research on the experimental rock mechanics of rockburst under unloading condition. J Chongqing Jiao Tong Univ 22:1–4Google Scholar
  32. Xu LS, Wang LS, Li TB, Xu J, Jin XG (1999) Study on the character of rockburst and its forecasting in the erlangmountain tunnel. J Geol Hazards Environ Preserv 10(2):55–59Google Scholar
  33. Yang SQ, Xu WY (2004) Numerical simulation of strength-size effect of rock materials under different confining pressures. Chin J Rock Mech Eng 5:578–582 (In Chinese) Google Scholar
  34. Yang SQ, Su CD, Xu WY (2005) Experimental and theoretical study of size effect of rock material. Eng Mech 22(4):112–118CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  1. 1.School of Resources and EnvironmentNorth China University of Water Resources and Electric PowerZhengzhouChina
  2. 2.State Key Laboratory for GeoMechanics and Deep Underground EngineeringBeijingChina

Personalised recommendations