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In-situ Rock Spalling Strength near Excavation Boundaries

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Abstract

It is widely accepted that the in-situ strength of massive rocks is approximately 0.4 ± 0.1 UCS, where UCS is the uniaxial compressive strength obtained from unconfined tests using diamond drilling core samples with a diameter around 50 mm. In addition, it has been suggested that the in-situ rock spalling strength, i.e., the strength of the wall of an excavation when spalling initiates, can be set to the crack initiation stress determined from laboratory tests or field microseismic monitoring. These findings were supported by back-analysis of case histories where failure had been carefully documented, using either Kirsch’s solution (with approximated circular tunnel geometry and hence σ max = 3σ 1 −σ 3) or simplified numerical stress modeling (with a smooth tunnel wall boundary) to approximate the maximum tangential stress σ max at the excavation boundary. The ratio of σ max /UCS is related to the observed depth of failure and failure initiation occurs when σ max is roughly equal to 0.4 ± 0.1 UCS. In this article, it is suggested that these approaches ignore one of the most important factors, the irregularity of the excavation boundary, when interpreting the in-situ rock strength. It is demonstrated that the “actual” in-situ spalling strength of massive rocks is not equal to 0.4 ± 0.1 UCS, but can be as high as 0.8 ± 0.05 UCS when surface irregularities are considered. It is demonstrated using the Mine-by tunnel notch breakout example that when the realistic “as-built” excavation boundary condition is honored, the “actual” in-situ rock strength, given by 0.8 UCS, can be applied to simulate progressive brittle rock failure process satisfactorily. The interpreted, reduced in-situ rock strength of 0.4 ± 0.1 UCS without considering geometry irregularity is therefore only an “apparent” rock strength.

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References

  • Bieniawski ZT (1967) Mechanism of brittle fracture of rock, Parts I, II and III. Int J Rock Mech Min Sci Geomech Abstr 4(4):395–430

    Article  Google Scholar 

  • Bieniawski ZT (1972) Propagation of brittle fracture in rock. In: Proceedings 10th Symposium on Rock Mech. (AIME), pp 409–427

  • Bieniawski ZT, Van Herdeen WI (1975) The significance of in-situ tests on large rock specimens. Int J Rock Mech Min Sci 12(4):101–113

    Article  Google Scholar 

  • Brace WF, Paulding B, Scholz C (1966) Dilatancy in the fracture of crystalline crocks. J Geophys Res 71(16):3939–3953

    Article  Google Scholar 

  • Cai M (2008) Influence of intermediate principal stress on rock fracturing and strength near excavation boundaries—insight from numerical modeling. Int J Rock Mech Min Sci 45(5):763–772

    Article  Google Scholar 

  • Cai M (2011) Rock mass characterization and rock property variability considerations for tunnel and cavern design. Rock Mech Rock Engng 44(4):379–399

    Article  Google Scholar 

  • Cai M, Kaiser PK (2004) Numerical simulation of the Brazilian test and the tensile strength of anisotropic rocks and rocks with pre-existing cracks. Int J Rock Mech Min Sci 41(Supplement 1):478–483

    Article  Google Scholar 

  • Cai M, Kaiser PK, Tasaka Y, Maejima T, Morioka H, Minami M (2004a) Generalized crack initiation and crack damage stress thresholds of brittle rock masses near underground excavations. Int J Rock Mech Min Sci 41(5):833–847

    Article  Google Scholar 

  • Cai M, Kaiser PK, Uno H, Tasaka Y, Minami M (2004b) Estimation of rock mass strength and deformation modulus of jointed hard rock masses using the GSI system. Int J Rock Mech Min Sci 41(1):3–19

    Article  Google Scholar 

  • Cai M, Kaiser PK, Morioka H, Minami M, Maejima T, Tasaka Y, Kurose H (2007a) FLAC/PFC coupled numerical simulation of AE in large-scale underground excavations. Int J Rock Mech Min Sci 44(4):550–564

    Article  Google Scholar 

  • Cai M, Kaiser PK, Suorineni F, Su K (2007b) A Study on the dynamic behaviour of the meuse/haute-marne argillite. Phys Chem Earth 32(8–14):907–916

    Article  Google Scholar 

  • Carter BJ (1992) Size and stress gradient effects on fracture around cavities. Rock Mech Rock Engng 25:167–186

    Article  Google Scholar 

  • Cundall PA (1994) Modeling of notch formation in the URL Mine-by tunnel, Report to URL/AECL. Itasca Consulting Group Inc., p 15

  • Cundall PA, Pierce ME, Mas Ivars D (2008) Quantifying the size effect of rock mass strength. In: SHIRMS 2008 pp 3–15

  • Diederichs MS (2007) The 2003 canadian geotechnical colloquium: mechanistic interpretation and practical application of damage and spalling prediction criteria for deep tunnelling. Can Geotech J 44(9):1082–1116

    Article  Google Scholar 

  • Einstein HH, Baecher GB, Hirschfeld RC (1970) The effect of size on strength of a brittle rock. In: Proceedings 2rd International Congress on Rock Mechanics, International Society for Rock Mechanics, pp 7–13

  • Elmo D, Rogers S, Beddoes R (2011) Numerical analysis of caving mechanism using a hybrid FEM/DEM approach: experience gained and lessons learned. In: 45th US Symp. Rock Mech, San Francisco

  • Emsley S, Olsson O, Stenberg L, Alheid HJ, Falls S (1997). ZEDEX A study of damage and disturbance from tunnel excavation by blasting and tunnel boring. Swedish Nuclear Fuel and Waste Management Co. p 198

  • Ewy RT, Cook NGW (1990) Deformation and fracture around cylindrical openings in rock—I, observations and analysis of deformations. Int J Rock Mech Min Sci Geomech Abstr 27:387–407

    Article  Google Scholar 

  • Exadaktylos G, Stavropoulou M (2008) A specific upscaling theory of rock mass parameters exhibiting spatial variability: analytical relations and computational scheme. Int J Rock Mech Min Sci 47(7):1102–1125

    Article  Google Scholar 

  • Golchinfar N, Cai M (2012) Modeling depth of failure using brittle Mohr-Coulomb failure model. In: Proceedings 21st Canadian Rock Mech. Symp., Edmonton, pp 127–135

  • Goodman RE (1989) Introduction to Rock Mechanics. John Wiley & Sons p 562

  • Hajiabdolmajid V, Kaiser PK, Martin CD (2000) Modelling brittle failure of rock. In: Proceedings 4th North American Rock Mech. Symposium, Seattle, pp 991–998

  • Hoek E (1965) Rock fracture under static stress conditions. National Mechanical Eng. Research Institute, Council for Scientific and Industrial Research, Pretoria

    Google Scholar 

  • Hoek E, Brown ET (1980) Underground excavations in rock. Institution of Mining and Metallurgy, London 527

    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, Carranza Torres C, Corkum B (2002) Hoek-Brown failure criterion—2002 edition. In: Proceedings 5th North American Rock Mech. Symposium, Toronto, Canada, pp 267–273

  • Hsiao FY, Wang CL, Shao HJ (2011) Mechanical parameters estimation and tunnel deformation study for brittle rock under high overburden condition. Rock soil mech 32(S2):109–114

    Google Scholar 

  • Jackson R, Lau JSO (1990) The effect of specimen size on the laboratory mechanical properties of Lac du Bonnet grey granite. In: Scale effects in rock masses, Balkema, Rotterdam

  • Kaiser PK, Kim BH (2012) Characterization of strength of intact brittle rock considering confinement-dependent failure processes. Rock Mech Rock Engng. submitted

  • Kaiser PK, Tannant DD, McCreath DR (1996) Canadian rockburst support handbook. Geomechanics Research Centre, Laurentian University, Sudbury 314

    Google Scholar 

  • Kaiser PK, Diederichs MS, Martin CD, SharpJ, Steiner W (2000) Underground works in hard rock tunnelling and mining. In: Keynote lecture at GeoEng2000, Technomic Publishing Co., Melbourne, Australia, pp 841–926

  • Kaiser PK, Kim BH, Bewick R, Valley B (2010) Rock mass strength at depth and implications for pillar design. In: 5th International Seminar on Deep and High Stress Mining, Santiago, Chile, pp 463–476

  • Laigle F (2006) Short-term and delayed behaviors of underground openings—field observations and numerical simulations. In: Proceedings 4th International FLAC Symposium, Madrid, Paper No. 02-08

  • Lajtai EZ, Schmidtke H (1986) Delayed failure in rock loaded in uniaxial compression. Rock Mech 19:11–25

    Article  Google Scholar 

  • Lajtai EZ, Scott Duncan EJ, Carter BJ (1991) The effect of strain rate on rock strength. Rock Mech Rock Engng 24:99–109

    Article  Google Scholar 

  • Lankford J (1981) The role of tensile microfracture in the strain rate dependence of the compressive strength of fine-grained limestone-analogy with strong ceramics. Int J Rock Mech Min Sci Geomech Abstr 18(1):173–175

    Article  Google Scholar 

  • Lockner DA (1995) “Rock failure”. Rock physics and phase relations, rock physics and phase relations. Am Geophys Un 127–147

  • Ma GW, An XM, Zhang HH, Li LX (2009) Modeling complex crack problems using the numerical manifold method. Int J Fracture 151(1):21–35

    Article  Google Scholar 

  • Ma K, Tang CA, Li LC, Ranjith PG, Cai M, Xu NW (2012) 3D modeling of stratified and irregularly jointed rock slope and its progressive failure. Arabian J Geosci doi: 10.1007/s12517-012-0578-6)

  • Martin CD (1995) Brittle rock strength and failure: Laboratory and in situ. In: 8th ISRM, A.A. Balkema, Rotterdam, pp 1033–1040

  • Martin CD (1997) Seventeenth Canadian geotechnical colloquium: the effect of cohesion loss and stress path on brittle rock strength. Can Geotech J 34(5):698–725

    Article  Google Scholar 

  • Martin CD, Martino JB, Dzik EJ (1994) Comparison of borehole breakouts from laboratory and field tests. In: Eurock’ 94, Balkema, pp 183–190

  • Martin CD, Kaiser PK, McCreath DR (1999) Hoek-Brown parameters for predicting the depth of brittle failure around tunnels. Can Geotech J 36(1):136–151

    Article  Google Scholar 

  • Mogi K (1962) The influence of the dimensions of specimens on the fracture strength of rocks. Bull Earthquake Res Inst (The University of Tokyo) 40:175–185

    Google Scholar 

  • Myrvang A M (1991) Estimation of in situ compressive strength of rocks from in situ stress measurements in highly stressed rock structures. In: 7th ISRM, A. Balkema, Rotterdam,pp 573–75

  • Napier JAL, Daehnke A, Dede T, Hildyard MW, Kuijpers JS, Malan DF, Sellers EJ, Turner PA (1997) Quantification of stope fracture zone behaviour in deep level gold mines. J. South Afr. Inst. Min. Metall (May/June) pp 119–134

  • Olsson WA (1991) The compressive strength of Tuff as a function of strain rate from 10–6 to 103 sec. Int J Rock MechMin Sci Geomech Abstr 28:115–118

    Article  Google Scholar 

  • Pelli F, Kaiser PK, Morgenstern NR (1991) An interpretation of ground movements recorded during construction of the Donkin-Morien tunnel. Can Geotech J 28(2):239–254

    Article  Google Scholar 

  • Potyondy D, Cundall PA (1999) Modeling of notch formation in the URL Mine-By tunnel: Phase IV, enhancements to the PFC model of rock. Itasca Consulting Group Inc

  • Potyondy D, Cundall PA (2004) A bonded-particle model for rock. Int J Rock Mech Min Sci 41(8):1329–1364

    Article  Google Scholar 

  • Pratt HR, Black AD, Brown WS, Brace WF (1972) The effect of speciment size on the mechanical properties of unjointed diorite. Int. J. Rock Mech. Min. Sci. Geomech Abstr 9(4):513–516

    Article  Google Scholar 

  • Read RS, Chandler NA, Dzik EJ (1998) In situ strength criteria for tunnel design in highly-stressed rock masses. Int J Rock Mech Min Sci 35(3):261–278

    Article  Google Scholar 

  • Roberts DP, Sellers EJ, Sevume C (1999) Numerical modelling of fracture zone development and support interaction for a deep level tunnel in a stratified rockmass. In: SARES 99. SANIRE, Johannesburg, pp 264–272

  • Shen B, Stephansson O, Rinne M (2002) Simulation of borehole breakouts using FRACOD2D. Oil Gas Sci Technol 57(5):579–590

    Article  Google Scholar 

  • Shi GH (1991) Manifold method of material analysis. In: Trans 9th Army Conf on Applied Mathematics and Computing, Minneapolis, Minnesota, pp 57–76

  • Singh MM, Huck PJ (1973) Large scale triaxial tests on rock. In: Proceedings 14th Symposium on Rock Mechanics, ASCE, Penn. State University, pp 35–60

  • Stacey TR (1981) A simple extension strain criterion for fracture of brittle rock. Int J Rock MechMin Sci Geomech Abstr 18:469–474

    Article  Google Scholar 

  • Stacey TR, Yathavan K (2003) Examples of Fracturing of Rock at Very Low Stress Levels. In: ISRM 2003 Technology roadmap for rock mechanics, pp 1155–1159

  • Tang CA (1997) Numerical simulation of progressive rock failure and associated seismicity. Int J Rock Mech Min Sci 34:249–262

    Article  Google Scholar 

  • Wiseman N (1979) Factors affecting the design and condition of mine tunnels. Chamb Mines S Afr, Pretoria 22

    Google Scholar 

Download references

Acknowledgments

Financial support from the Natural Sciences and Engineering Research Council (NSERC) of Canada is greatly appreciated.

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  1. Bharti School of Engineering, Laurentian University, Sudbury, ON, Canada

    M. Cai

  2. Centre for Excellence in Mining Innovation, Sudbury, ON, Canada

    P. K. Kaiser

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Correspondence to M. Cai.

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Cai, M., Kaiser, P.K. In-situ Rock Spalling Strength near Excavation Boundaries. Rock Mech Rock Eng 47, 659–675 (2014). https://doi.org/10.1007/s00603-013-0437-0

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