Tunnel and Underground Space (터널과지하공간)

Korean Society for Rock Mechanics and Rock Engineering (한국암반공학회)
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Relationship between Tangential Cohesion and Friction Angle Implied in the Generalized Hoek-Brown Failure Criterion

일반화된 Hoek-Brown 파괴조건식에 내포된 접선점착력과 접선마찰각의 상관성

  • Lee, Youn-Kyou (Department of Coastal Construction Engineering, Kunsan National University)
  • 이연규 (군산대학교 해양과학대학 해양건설공학과)
  • Received : 2014.09.12
  • Accepted : 2014.09.26
  • Published : 2014.10.31
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Abstract

The generalized Hoek-Brown (H-B) function provides a unique failure condition for a jointed rock mass, in which the strength parameters of rock mass are deduced from the intact values by use of the GSI value. Since it is actually the only failure criterion which accounts for the rock mass conditions in a systematic manner, the generalized H-B criterion finds many applications to the various rock engineering projects. Its nonlinear character, however, limits more active usage of this criterion. Accordingly, many attempts have been made to understand the generalized H-B condition in the framework of the M-C function. This study presents the closed-form expression relating the tangential cohesion to the tangential friction angle, which is derived by the non-dimensional stress transformation of the generalized H-B criterion. By use of the derived equation, it is investigated how the relationship between the tangential cohesion and friction angle of the generalized H-B criterion varies with the quality of rock masses. When only the variation of GSI value is considered, it is found that the tangential friction angle decreases with the increase of GSI, while the tangential cohesion increases with GSI value.

일반화된 Hoek-Brown (H-B) 식은 절리성 현장암반에 적용되는 암반공학 고유의 파괴조건식이다. 이 파괴조건식에서는 현장암반의 GSI 값을 이용하여 무결암의 강도정수를 현장암반의 값으로 변환시킨다. 현장암반의 특성을 체계적으로 고려한 거의 유일한 암반파괴조건식이라는 측면에서 일반화된 H-B 파괴조건식은 적용범위를 넓혀가고 있지만 비선형 함수라는 단점을 가지고 있다. 이에 따라 일반화된 H-B 식을 선형 Mohr-Coulomb (M-C) 파괴조건식의 틀로 이해하려는 연구들이 시도되고 있다. 이 연구에서는 일반화된 H-B 식에 응력무차원화 변환을 적용하여 접선점착력을 접선마찰각의 함수로 표현하는 명시적 관계식을 유도하였다. 유도된 관계식을 이용하여 암반 질의 변화에 따른 일반화된 H-B 식에 내포된 접선마찰각 - 접선점착력 변화 특성을 고찰하였다. GSI 값의 변화만을 고려한 경우 GSI 값의 증가에 따라 접선마찰각은 감소하고 접선점착력은 증가하는 경향을 보였다.

Keywords

References

  1. Balmer, G., 1952, A general analytical solution for Mohr's envelope, Proc. ASTM, Vol. 52, pp. 1260-1271.
  2. Davis, R.O. and Sevadurai, A.P.S., 2002, Plasticity and Geomechanics, Cambridge University Press.
  3. Deb, D. and Choi, S.O., 2005, Comparison between direct and indirect implementation of generalized Hoek and Brown failure criterion in numerical analysis procedure, J. Korean Soc. Rock Mech. (Tunnel and Underg. Space), Vol. 15(3), pp. 228-235.
  4. Hoek, E. and Brown, E.T., 1980, Underground Excavations in Rock, London: Insti. Min. Metall.
  5. Hoek, E., 1983, Strength of jointed rock masses, Geotechnique, Vol. 33(3), pp. 187-223. https://doi.org/10.1680/geot.1983.33.3.187
  6. Hoek, E. and Brown, E.T., 1988, The Hoek-Brown failure criterion - a 1988 update, Proc. 15th Canadian Rock Mech. Symp., Univ. of Toronto, pp. 31-38.
  7. Hoek, E., 1990, Estimating Mohr-Coulomb friction ang cohesion values from the Hoek-Brown failure criterion, Int. J. Rock Mech. Min. Sci. & Geomech. Abstr., Vol. 27(3), pp. 227-229.
  8. Hoek, E., Kaiser, P.K. and Bawden, W.F., 1995, Support of underground excavation in hard rock, A.A. Balkema.
  9. Hoek, E., Carranza-Torres, C. and Corkum, B., 2002, Hoek-Brown failure criterion - 2002 Edition, Proc. NARM-TAC Conf., Toronto, Vol. 1, pp. 267-273.
  10. Hoek, E. and Marinos, P., 2007, A brief history of the development of the Hoek-Brown failure criterion, Soils and Rocks, No. 2.
  11. Lee, Y.-K. and Choi, B.-H, 2012, Equivalent friction angle and cohesion of the generalized Hoek-Brown failure criterion in terms of stress invariants, J. Korean Soc. Rock Mech. (Tunnel & Undergr. Space), Vol. 22(6), pp. 462-470. https://doi.org/10.7474/TUS.2012.22.6.462
  12. Lee, Y.-K. and Choi, B.-H., 2013, Dependency of tangential friction angle and cohesion of non-linear failure criterion on the intermediate principal stress, J. Korean Soc. Rock Mech. (Tunnel & Undergr. Space), Vol. 23(3), pp. 219-227. https://doi.org/10.7474/TUS.2013.23.3.219
  13. Lee, Y.-K., 2014, Derivation of Mohr envelope of Hoek-Brown failure criterion using non-dimensional stress transformation, J. Korean Soc. Rock Mech. (Tunnel & Undergr. Space), Vol. 24(1), pp. 81-88. https://doi.org/10.7474/TUS.2014.24.1.081
  14. Londe, P., 1988, Discussion on the determination of the shear stress failure in rock masses, ASCE J. Geotech. Eng. Div., Vol. 14(3), pp. 374-376.
  15. Ucar, R., 1986, Determination of shear failure envelope in rock masses, J. Geotech. Eng. Div. ASCE, Vol. 122(3), pp. 303-315.
  16. Yang, X.-L. and Yin, J.-H., 2005, Upper bound solution for ultimate bearing capacity with a modified Hoek-Brown failure criterion, Int. J. Rock Mech. & Min. Sci., Vol. 42, pp. 550-560. https://doi.org/10.1016/j.ijrmms.2005.03.002
  17. Yang, X.-L. and Yin, J.-H., 2006, Linear Mohr-Coulomb strength parameters from the non-linear Hoek-Brown rock masses, Int. J. Non-Linear Mech., Vol. 41, pp. 1000-1005. https://doi.org/10.1016/j.ijnonlinmec.2006.08.003

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