Development of Classification Charts for Q Index of Shale from the Parameters

  • Nandyala Darga KumarEmail author
  • Ravikant R. Singh
  • Faijal Ali
  • Efray’im
Conference paper
Part of the Springer Series in Geomechanics and Geoengineering book series (SSGG)


Construction of tunnels, slopes, deep basements, foundations and retaining walls are common in shale. Quality of shale can be assessed based on the Q index system. This paper presents the analysis of charts developed for Q index of shale from three different parameters such as block size (RQD/Jn), inter-block shear strength (Jr/Ja) and active stress (Jw/SRF). For the range of values chosen for RQD/Jn, Jr/Ja and Jw/SRF a Q index was estimated and charts were established between Q index and RQD/Jn for various values of Jr/Ja and Jw/SRF. The charts presented in the paper for Q index can be used to classify the shale. Shale should have minimum Jr/Ja, Jw/SRF and RQD/Jn as 0.5, 0.2 and 10 respectively to be classified as good to very good category.


Shear Strength Block Size Unconfined Compressive Strength Black Shale Active Stress 
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  1. Barton NR (2002) Some new Q-value correlations to assist in site characterization and tunnel design. Int J Rock Mech Min Sci 39(2):185–216. doi: 10.1016/S1365-1609(02)00011-4 MathSciNetCrossRefGoogle Scholar
  2. Barton NR, Lien R, Lunde J (1974) Engineering classification of rock masses for the design of tunnel support. Rock Mech Rock Eng 6(4):189–236. doi: 10.1007/BF01239496 SpringerCrossRefGoogle Scholar
  3. Bertuzzi R, Pells PJN (2002) Geotechnical parameters of Sydney stone and shale. Aust Geomech 37(5):41–54Google Scholar
  4. Bonini M, Debernardi D, Barla M, Barla G (2009) The mechanical behaviour of clay shales and implications on the design of tunnels. Rock Mech Rock Eng 42:361. doi: 10.1007/s00603-007-0147-6 CrossRefGoogle Scholar
  5. Britt LK, Schoeffler J (2009) The geomechanics of a shale play: what makes a shale prospective. SPE Eastern Regional Meeting, Society of Petroleum Engineers, 9 ppGoogle Scholar
  6. Chang C, Zoback MD, Khaksar A (2006) Empirical relations between rock strength and physical properties in sedimentary rocks. J Petrol Sci Eng 51:223–237. ElsevierGoogle Scholar
  7. Coveney RM (2003) Metalliferous paleozoic black shales and associated strata. In: Lenz DR (ed) Geochemistry of sediments and sedimentary rocks Geotext, vol 4. Geological Association of Canada, pp 135–144Google Scholar
  8. Derek Martin C (2015) Behaviour of shales in underground environments. In: 13th ISRM international congress of rock mechanics, 10–13 May, Montreal. International Society for Rock Mechanics. ISBN 978-1-926872-25-4Google Scholar
  9. Einstein HH (2000) Tunnels in Opalinus clay shale-a review of case histories and new developments. Tunn Undergr Space Technol 15(1):13–29. Elsevier Science Ltd.Google Scholar
  10. Hartman W, Handley MF (2002) The application of the Q-tunneling quality index to rock mass assessment at Impala Platinum mine. J S Afr Inst Min Metall 102(3):155–165Google Scholar
  11. Derakhshandeh M (1989) Monitoring of nondurable shale fills in semi – arid climates, Report No. CDOH-DTD-R-89-8, Colorado Department of Highways, ColoradoGoogle Scholar
  12. Shakoor A, Rodgers JP (1992) Predicting the rate of shale undercutting along highway cuts. Environ Eng Geosci. doi: 10.2113/gseegeosci.xxix.1.61 Google Scholar
  13. Winter MG (2001) Spent oil shale use in earthwork construction. Eng Geol 60(1–4):285–294. Special issue on geoenvironmental engineeringGoogle Scholar

Copyright information

© Springer International Publishing AG 2017

Authors and Affiliations

  • Nandyala Darga Kumar
    • 1
    Email author
  • Ravikant R. Singh
    • 1
  • Faijal Ali
    • 1
  • Efray’im
    • 1
  1. 1.Fiji National UniversitySuvaFiji Islands

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