Skip to main content

Advertisement

SpringerLink
Log in

Comparison of different approaches and development of improved formulas for estimating GSI

  • Original Paper
  • Published:
Bulletin of Engineering Geology and the Environment Aims and scope Submit manuscript

Abstract

The Geological Strength Index (GSI) is an important parameter for estimating rock mass properties and can be estimated either through direct observations or by using a quantitative GSI chart or equations. This study aims to discuss the applicability of the RMR89 method and the latest version of GSI|2013 by applying them to a case study and to the data published in the earlier papers. The relevant rock mass properties, including blockiness and discontinuity conditions, of the walls of 15 exploratory adits with a total length longer than 1100 m in a hydropower project in China have been assessed to provide data for the analysis. In addition, a repeat analysis of the earlier published data has been conducted to validate the results derived from the case study. The results show that the GSI values calculated with the RMR89 are generally larger than those obtained from the qualitative GSI chart, with an average magnitude of about five. The GSI values predicted from the values of JCond89 and RQD are consistent with those derived through the qualitative observational method for a medium-quality rock mass but are relatively smaller or larger for a poor-quality (i.e., GSI<45) or a high-quality (i.e. GSI>65) rock mass, respectively. By comparing the results of the RMR89 method and the qualitative GSI chart method and analyzing the classification factors considered by the two methods, two new equations based on the RMR89 system have been developed for estimating the GSI. Their application to the case study and the published data prove that these two equations have higher predictive accuracy than the original RMR89 method and the latest version of GSI|2013. It is expected that the acquisition of more engineering examples will enable the two formulas to be further verified and improved.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12

Similar content being viewed by others

References

  • Ali W, Mohammad N, Tahir M (2014) Rock mass characterization for diversion tunnels at Diamer Basha dam, Pakistan – a design perspective. Int J Sci Eng Technol 3(10):1292–1296

    Google Scholar 

  • Barton N, Lien R, Lunde J (1974) Engineering classification of rock masses for the design of tunnel support. Rock Mech 6:189–236

    Article  Google Scholar 

  • Anbalagan R, Singh B, Bhargava P (2003) Half tunnels along hill roads of Himalaya—an innovative approach. Tunnel Undergr Space Tech 18(4):411–419

    Article  Google Scholar 

  • Basarir H, Ozsan A, Karakus M (2005) Analysis of support requirements for a shallow diversion tunnel at Guledar dam site, Turkey. Eng Geol 81:131–145

    Article  Google Scholar 

  • Bertuzzi R, Douglas K, Mostyn G (2016) Comparison of quantified and chart GSI for four rock masses. Eng Geol 202(2016):24–35

    Article  Google Scholar 

  • Bieniawski ZT (1989) Engineering rock mass classifications. John Wiley & Sons

  • Bieniawski ZT (1976) Rock mass classifications in rock engineering. Proceedings of the Symposium on Exploration for Rock Engineering, Johannesburg

    Google Scholar 

  • Cai M, Kaiser PK, Uno H, Tasaka Y, Minami M (2004) Estimation of rock mass deformation modulus and strength of jointed hard rock masses using the GSI system. Int J Rock Mech Min Sci 41:3–19

    Article  Google Scholar 

  • Dalgic S (2003) Tunneling in fault zones, Tuzla tunnel, Turkey. Tunnell Undergr Space Tech 18(5):453–465

    Article  Google Scholar 

  • Dalgic S (2002) A comparison of predicted and actual tunnel behavior in the Istanbul metro, Turkey. Eng Geol 63:69–83

    Article  Google Scholar 

  • Hoek E, Brown ET (2018) The Hoek-Brown failure criterion and GSI –2018 edition. J Rock Mech Geotech Eng. https://doi.org/10.1016/j.jrmge.2018.08.00

  • Hoek E, Carter TG, Diederichs MS (2013) Quantification of the geological strength index chart. In: 47th US rock mechanics/geomechanics symposium, American Rock Mechanics Association (ARMA 13–672)

  • Hoek E, Marinos P (2000) Predicting tunnel squeezing. Tunnels and Tunnelling international. Part 1 – November 2000, Part 2 – December, 2000

  • Hoek E, Marinos P, Benissi M (1998) Applicability of the geological strength index (GSI) classification for very weak and sheared rock masses. The case of the Athens Schist Formation. Bull Eng Geol Environ 57:151–160

    Article  Google Scholar 

  • Hoek E, Brown ET (1997) Practical estimates of rock mass strength. Int J Rock Mech Min Sci 34(8):1165–1186

    Article  Google Scholar 

  • Hoek E, Kaiser PK, Bawden WF (1995) Support of underground excavations in hard rock. Balkema, Rotterdam

    Google Scholar 

  • Hoek E (1994) Strength of rock and rock masses. ISRM News J:4–16

  • Irvani I, Wilopo W, Karnawati D (2013) Determination of nuclear power plant site in west bangka based on rock mass rating and geological strength index. J Se Asian Appl Geol 5(2):78–86

    Google Scholar 

  • Justo J, Justo E, Durand P, Azanon J (2006) The foundation of a 40-story tower in jointed basalt. Int J Rock Mech Min Sci 43:267–281

    Article  Google Scholar 

  • Marinos P, Hoek E, Marinos V (2005) Variability of the engineering properties of rock masses quantified by the geological strength index: the case of ophioliteswith special emphasis on tunneling. Bull Eng Geol Environ 65:129–142

    Article  Google Scholar 

  • Marinos P, Hoek E (2001) Estimating the geotechnical properties of heterogeneous rock masses such as flysch. Bull Eng Geol Environ 60:85–92

    Article  Google Scholar 

  • Marinos P, Hoek E (2000) GSI: a geologically friendly tool for rock mass strength estimation

  • Marinos V (2019) 2019. A revised, geotechnical classification GSI system for tectonically disturbed heterogeneous rock masses, such as flysch. Bull Eng Geol Environ 78:899–912

    Article  Google Scholar 

  • Morelli GL (2015) 2015. Variability of the GSI index estimated from different quantitative methods. Geotech Geol Eng 33:983–995

    Article  Google Scholar 

  • Osgoui R, Ünal E (2005) Rock reinforcement design for unstable tunnels originally excavated in very poor rock mass. Underground space use. In: analysis of the past and lessons for the future, two volume set: proceedings of the international world tunnel congress and the 31st ITA general assembly, Istanbul, Turkey, 7-12 may 2005. CRC press, pp. 291–296

  • Palmstrom A (1995) RMi—a rock mass characterization system for rock engineering purposes. Ph.D. thesis, University of Oslo, Norway

  • Pells P (2002) Developments in the design of tunnels and caverns in the Triassic rocks of the Sydney region. Int J Rock Mech Min Sci 39:569–587

    Article  Google Scholar 

  • Polishook B, Flexer A (1998) Assessment of chalk rock mass in excavations. Bull Eng Geol Environ 57:145–150

    Article  Google Scholar 

  • Priest SD, Hudson JA (1981) Estimation of discontinuity spacing and trace length using scanline surveys. Int J Rock Mech Min Sci Geomech Abstr 18(3):183–197

    Article  Google Scholar 

  • Russo G (2009) A new rational method for calculating the GSI. Tunn Undergr Space Technol 24:103–111

    Article  Google Scholar 

  • Santa C, Gonçalves L, ChaminéH I (2019) A comparative study of GSI chart versions in a heterogeneous rock mass media (Marão tunnel, North Portugal): a reliable index in geotechnical surveys and rock engineering design. Bull Eng Geol Environ. https://doi.org/10.1007/s10064-019-01481-7

  • Singh JL, Tamrakar NK (2013) Rock mass rating and geological strength index of rock masses of Thopal-Malekhu river areas, Central Nepal lesser Himalaya. Bull Dept Geol 16:29–42

    Article  Google Scholar 

  • Sonmez H, Ulusay R (2002) A discussion on the Hoek-Brown failure criterion and suggested modifications to the criterion verified by slope stability case studies. Yerbilimleri (Earthsciences; http://www.yerbilimleri.hacettepe.edu.tr/no26/yb26txt6.pdf), 26, 77-99

  • Sonmez H, Ulusay R (1999) Modification to the geological strength index (GSI) and their applicability to stability of slopes. Int J Rock Mech Min Sci 36:743–760

    Article  Google Scholar 

  • Wang Y, Aladejare AE (2016) Evaluating variability and uncertainty of geological strength index at a specific site. Rock Mech Rock Eng 49(2016):3559–3573

    Article  Google Scholar 

  • Winn K, Ngai L, Wong Y (2019) 2019. Quantitative GSI determination of Singapore’s sedimentary rock mass by applying four different approaches. Geotech Geol Eng 37:2103–2119. https://doi.org/10.1007/s10706-018-0748-8

    Article  Google Scholar 

  • Zhang Q, Huang X, Zhu H, Li J (2019) Quantitative assessments of the correlations between rock mass rating (RMR) and geological strength index (GSI). Tunn Undergr Space Technol 83(2019):73–81

    Article  Google Scholar 

Download references

Funding

This research was financially supported by the Fundamental Research Funds for the Central Universities, CHD (No. 300102269202).

Author information

Authors and Affiliations

  1. School of Geology Engineering and Geometrics, Chang′an University, Xi′an, 710054, China

    Yanhui Song & Huishi Xue

  2. Key Laboratory of Western Mineral Resources and Geological Engineering Ministry of Education, Xi′an, 710054, China

    Yanhui Song

  3. Northwest Engineering Corporation Limited, Xi′an, 710065, China

    Guanghong Ju

Authors
  1. Yanhui Song
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Huishi Xue
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Guanghong Ju
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Yanhui Song.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Song, Y., Xue, H. & Ju, G. Comparison of different approaches and development of improved formulas for estimating GSI. Bull Eng Geol Environ 79, 3105–3119 (2020). https://doi.org/10.1007/s10064-020-01739-5

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10064-020-01739-5

Keywords

Search

Navigation