Analyzing Drill Core Logging Using Rock Quality Designation–60 Years’ Experience from Modifications to Applications
Source abstract
Abstract
The accurate analysis of rock cores is of primary importance for designing in and on the rock mass environment. There are several methods for analyzing boreholes, but the most accepted and widely used method is the rock quality designation (RQD) value, which has been a core rating metric for six decades. The RQD value serves as: (1) an important input parameter for rock mass classifications such as RMR and Q; (2) a basis for calculating the Geological Strength Index (GSI) of boreholes; and (3) a key indicator in assessing rock mass quality, particularly in highly fractured or weak rock masses. The original RQD method has several drawbacks and shortcomings, which have led to numerous proposed amendments. This review paper aims to: (1) summarize alternative methods of calculating the RQD value; (2) analyze the sensitivity of different rock mass classifications to the accuracy of this value; and (3) present a systematic analysis of the practical implications of modified RQD methods, emphasizing advancements such as DFN modeling, seismic RQD techniques, and machine learning-based approaches. The findings provide a comprehensive framework for more robust and versatile assessments of rock mass quality.
Source: crossref · Quality: baseline
Research context
OpenAlex topics: Tunneling and Rock Mechanics · Rock Mechanics and Modeling · Drilling and Well Engineering
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
Department of Engineering Geology and Geotechnics, Faculty of Civil Engineering, Budapest University of Technology and Economics, Műegyetem rkp 3, H-1111 Budapest, Hungary
Research Institute of Mines and Environment (RIME), Université du Québec en Abitibi-Témiscamingue (UQAT), Rouyn-Noranda, QC J9X 5E4, Canada
Gecko Geotechnics LLC., P.O. Box 1574, Kingstown VC0100, Saint Vincent and the Grenadines
References (75)
Show source-provided references
1. Technical description of rock cores for engineering purposes
2. Deere, D.U., Hendron, A.J., Patton, F.D., and Cording, E.J. (1966, January 15–17). Design of surface and near surface construction in rock. Proceedings of the 8th U.S. Symposium on Rock Mechanics-Failure and Breakage of Rock, Minneapolis, MN, USA.
3. Hoek, E., Kaiser, P.K., and Bawden, W.F. (1995). Support of Underground Excavations in Hard Rock, Taylor & Francis.
4. Rock mass classification in rock engineering
5. Bieniawski, Z.T. (1989). Engineering Rock Mass Classification, Wiley Interscience.
6. Engineering classification of rock masses for the design of tunnel support10.1007/BF01239496 ↗
7. Hoek, E., Carter, T.G., and Diederichs, M.S. (2013, January 23–26). Quantification of the Geological Strength Index chart. Proceedings of the 47th US Rock Mechanics/Geomechanics Symposium, San Francisco, CA, USA. ARMA 13-672.
8. Deere, D.U. (1989). Rock Quality Designation (RQD) After Twenty Years, U.S. Army Corps of Engineers Contract Report GL-89-1.
9. Deere, D.U., and Deere, D.W. (1988). The Rock Quality Designation (RQD) index in practice. Rock Classification Systems Engineering Purposes, ASTM International. ASTM Special Technical Publication 984.10.1520/STP48465S ↗
10. (2024, December 26). Eurocode 1997-1: Geotechnical Design, Part 1: General Rules. Available online: https://www.ngm2016.com/uploads/2/1/7/9/21790806/eurocode_7_-_geotechnical_designen.1997.1.2004.pdf.
11. Sharma, V.M., and Saxena, K.R. (2001). Measurement and characterization of rock mass jointing. In Situ Characterization of Rocks, A.A. Balkema.
12. Measurements of and correlations between block size and rock quality designation (RQD)10.1016/j.tust.2005.01.005 ↗
13. Investigation of RQD variation with scanline length and optimal threshold based on three-dimensional fracture network modeling10.1007/s11431-013-5132-6 ↗
14. A Framework for RQD Calculation Based on Deep Learning
15. Rock mass characterization for underground hard rock mines10.1016/S0886-7798(98)00081-9 ↗
16. The concept of representative elementary length (REL) as an effective tool to study scale effects in rock engineering problems10.21701/bolgeomin.131.3.001 ↗
17. Should the Use of Rock Quality Designation Be Discontinued in the Rock Mass Rating System?10.1007/s00603-018-1607-x ↗
18. Palmström, A. (1996, January 18–20). The weighted joint density method leads to improved characterization of jointing. Proceedings of the Conference on Recent Advances in Tunnelling Technology, New Delhi, India.
19. Practical Investigations on Use of Weighted Joint Density to Decrease the Limitations of RQD Measurements10.1007/s00603-015-0788-9 ↗
20. Leung, C.F., and Zhou, Y.X. (2006). A proposal for the modification of RQD (MRQD). Rock Mechanics in Underground Construction, Proceedings of the ISRM International Symposium 4th Asian Rock Mechanics Symposium, Singapore, 8–10 November 2006, World Scientific.10.1142/6335 ↗
21. Li, L., Ouellet, S., and Aubertin, M. (2009, January 9–15). An improved definition of rock quality designation, RQDc. Proceedings of the 3rd CANUS Rock Mechanics Symposium, ROCKENG09, Toronto, ON, Canada.
22. A new method for improving the RQD determination of rock core in borehole10.1007/s00603-015-0789-8 ↗
23. Borehole analysis with the modification of RQD value10.3390/geotechnics3040055 ↗
24. Introducing Coefficients of Curvature (Cc) and Uniformity (Cu) Based on RQD for Rock Mass Characterization10.70425/rml.202501.10 ↗
25. Elmo, D., Yang, B., Stead, D., and Rogers, S. (2021). A discrete fracture network approach to rock mass classification. Challenges and Innovations in Geomechanics, Proceedings of the 16th International Conference of IACMAG, Turin, Italy, 5–8 May 2021, Springer.10.1007/978-3-030-64514-4_92 ↗
26. Wang, R., and Elmo, D. (2024). Discrete Fracture Network (DFN) as an Effective Tool to Study the Scale Effects of Rock Quality Designation Measurements. Appl. Sci., 14.10.3390/app14167101 ↗
27. Discontinuity spacing in rock10.1016/0148-9062(76)90818-4 ↗
28. Shen, W., Ni, W., Yong, R., Huang, L., Ye, J., Luo, Z., and Du, S. (2023). Estimating RQD for Rock Masses Based on a Comprehensive Approach. Appl. Sci., 13.10.3390/app132312855 ↗
29. Corrected Rock Fracture Parameters and Other Empirical Considerations for the Rock Mechanics of Rock Masses of Doha, Qatar10.1007/s10706-020-01658-y ↗
30. Russo, A., and Hormazabal, E. (2019). Correlations between various rock mass classification systems including Laubscher (MRMR), Barton (Q) and Hoek and Marinos (GSI) systems. Geotechnical Engineering in the XXI Century: Lessons and Future Challenges, IOS Press.
31. Palmström, A. (1982, January 31). The volumetric joint count—A useful and simple measure of the degree of rock mass jointing. Proceedings of the 4th Congress, International Association of Engineering Geology, New Delhi, India.
32. Integralgeometrische Bestimmung geotechnicsh wichtiger Klufteigenschaften10.1007/BF01239777 ↗
33. Vásárhelyi, B., and Bögöly, G. (2019, January 11–13). New method for determining the Geological Strength Index (GSI) value of boreholes. Proceedings of the Geotechnical Challenges in Karst, Omis-Split, Croatia.
34. Numerical determination of mechanical properties of rock and of rock masses10.1016/0148-9062(65)90014-8 ↗
35. A method of determining the degree of fissuration of rock10.1016/0148-9062(74)91108-5 ↗
36. Analyzing fissuring in boreholes and comparison of different methods10.1556/CEuGeol.50.2007.4.4 ↗
37. Building 3D Model of Rock Quality Designation Assisted by Co-Operative Inversion of Seismic and Borehole Data
38. Hasan, M., Shang, Y., and Meng, Q. (2023). Evaluation of rock mass units using a non-invasive geophysical approach. Sci. Rep., 13.10.1038/s41598-023-41570-y ↗
39. Assessment of geotechnical characterization of a rock mass using a seismic geophysical technique10.1007/BF00421945 ↗
40. Barton, N., Grimstad, E., Abrahão, R., and Bar, N. (2024). Q-Based Developments During the Last 50 Years, Fjellsprengningskonferansen.
41. Correlation of seismic P-wave velocities with engineering parameters (N value and rock quality) for tropical environmental study10.4236/ijg.2012.34075 ↗
42. Edelbro, C. (2003). Rock Mass Strength—A Review, Lulea University of Technology. Technical Report.
43. Determination and applications of rock quality designation (RQD)10.1016/j.jrmge.2015.11.008 ↗
44. Empirical methods of calculating the mechanical parameters of the rock mass
45. Coon, R.F., and Merritt, A.H. (1970). Predicting in situ modulus of deformation using rock quality indexes. Determination of the In Situ Modulus of Deformation of Rock, ASTM International.
46. Smith, R.W. (1987). Design of drilled piers in the Atlantic Piedmont. Foundations and Excavations in Decomposed Rock of the Piedmont Province, American Society of Civil Engineers (ASCE).
47. American Association of State Highway and Transportation Officials (AASHTO) (1996). Standard Specifications for Highway Bridges, AASHTO. [16th ed.].
48. Using RQD to estimate the deformation modulus of rock masses10.1016/S1365-1609(03)00100-X ↗
49. Vrkljan, I. (2010). Relation of rock mass characterization and damage. Rock Engineering in Difficult Conditions—Soft Rock and Karst, Routledge.10.1201/9781482288841 ↗
50. A nonlinear deformation modulus based on rock mass classification10.1007/BF01554041 ↗
51. Indirect determination of the modulus of deformation of rock masses based on GSI system10.1016/j.ijrmms.2003.01.006 ↗
52. Mitri, H.S., Edrissi, R., and Henning, J. (1994, January 14–17). Finite element modeling of cablebolted stopes in hard rock ground mines. Proceedings of the SME Annual Meeting, Albuquerque, NM, USA.
53. Carvalho, J. Estimation of Rock Mass Modulus. Personal communication, (Technische Universität Darmstadt, Darmstadt, Germany).
54. Empirical estimation of rock mass modulus10.1016/j.ijrmms.2005.06.005 ↗
55. Estimation of rock modulus: For intact rocks with an artificial neural network and for rock masses with a new empirical equation10.1016/j.ijrmms.2005.06.007 ↗
56. Hoek, E., Carranza-Torres, C., and Corkum, B. (2002, January 7–10). Hoek–Brown failure criterion—2002 edition. Proceedings of the 5th North American Rock Mechanics Symposium and 17th Tunnelling Association of Canada Conference: NARMS-TAC 2002, Toronto, ON, Canada.
57. Bell, F.G. (1987). Foundations in rock. Ground Engineer’s Reference Book, Butterworths. Chapter 15.
58. Estimating the strength of jointed rock masses10.1007/s00603-009-0065-x ↗
59. Strength and modulus response of anisotropic rocks
60. Effect of intermediate principal stress on strength of anisotropic rock mass10.1016/S0886-7798(98)00023-6 ↗
61. Empirical methods to estimate the strength of jointed rock masses10.1016/j.enggeo.2004.09.001 ↗
62. Stagg, K.G., and Zienkiewicz, O.C. (1968). Geological considerations. Rock Mechanics in Engineering Practice, Horizon Pubs & Distributors Inc.
63. Estimation of the Poisson’s ratio of the rock mass10.3311/PPci.22689 ↗
64. New Rock Mass Quality Rating System: Rock Mass Quality Rating (RMQR) and Its Application to the Estimation of Geomechanical Characteristics of Rock Masses10.1007/s00603-013-0462-z ↗
65. Sensitivity analysis of GSI based mechanical parameters of the rock mass10.3311/PPci.7507 ↗
66. Erharter, G., Hansen, T., Qi, S., Bar, N., and Marcher, T. (2023, January 9–14). A 2023 perspective on Rock Mass Classification Systems. Proceedings of the 15th ISRM Congress 2023 & 72nd Geomechanics Colloquium, Schubert & Kluckner, Salzburg, Austria.
67. Erharten, G.H., Bar, N., Hansen, T.F., Jain, S., and Marcher, T. (2024). International distribution and development of rock mass classification: A review. Rock Mech. Rock Eng.10.1007/s00603-024-04215-8 ↗
68. Hoek, E. (2007). Practical Rock Engineering, Rocscience. [Online ed.].
69. Zur Gebirgsklassifizierung bei Fräsvortrieben
70. Some new Q-value correlations to assist in site characterization and tunnel design10.1016/S1365-1609(02)00011-4 ↗
71. Mandl, G. (2005). Rock Joints: The Mechanical Genesis, Springer.
72. Strength of rock and rock masses
73. Singh, B., and Geol, R.K. (1999). Rock Mass Classification: A Practical Approach in Civil Engineering, Elsevier Science.
74. Applicability of the Geological Strength Index (GSI) classification for very weak and sheared rock masses. The case of the Athens Schist Formation10.1007/s100640050031 ↗
75. Yang, B., and Elmo, D. (2022). Why Engineers Should Not Attempt to Quantify GSI. Geosciences, 12.10.3390/geosciences12110417 ↗