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Research Article

A Study on Subcritical Crack Growth Parameters in Rock-like Material under Monotonic and Cyclic Loading

단조 및 반복하중 하에서의 모사 암석 시료의 임계하 균열성장 지수에 관한 연구

Tae Young Ko1*
고 태영1*
1SK Engineering & Construction, TBM Team
1SK건설 TBM팀
* Corresponding Author
30 April 2019. pp. 124-134
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Abstract

Subcritical crack growth in rock material can occur under monotonic and cyclic loading. Subcritical crack growth plays an important role in evaluating the long-term stability of structures in rocks. This paper presents the results of studies conducted to determine subcritical crack growth parameters under monotonic and cyclic loading in rock-like material. The constant stress rate method was employed for monotonic loading. The subcritical crack growth parameter of n under cyclic loading was determined by the relation between the rate of crack growth per cycle and stress intensity factor range. The specimens contained pre-existing flaws with 45 and 60 degrees of inclination angle and flaws spacing and continuity were varied to arrange crack growth in shear or tensile manner. The results show that the parameter of n is almost constant regardless of the applied load conditions such as monotonic and cyclic or shear and tension.

Keywords
Subcritical cack growth
Monotonic
Cyclic
Shear
Tension

암석에서의 임계하 균열성장은 단조 및 반복하중 하에서 일어날 수 있다. 임계하 균열 성장은 암반에 건설되는 지하구조물의 장기 안정성의 평가에 큰 영향을 미친다. 본 연구에서는 모사 암석 시료를 사용하여 단조 및 반복하중 하에서의 임계하 균열성장 지수를 구하였다. 단조하중 조건에서는 일정 응력 속도법이 적용되었으며, 반복하중에 의한 임계하 균열성장 지수는 반복에 의한 균열성장 속도와 응력확대계수폭의 관계를 이용하였다. 연구에 사용된 시험편은 45°와 60°의 균열 경사각을 가지고 있으며, 균열의 간격 및 연속성에 변화를 주어 전단 또는 인장에 의한 균열성장이 가능하도록 하여 전단 또는 인장에 의한 임계하 균열성장 지수도 구하였다. 그 결과, 임계하 균열성장 지수 n은 작용하는 하중 조건, 즉 단조 및 반복하중, 혹은 전단 및 인장에 관계없이 거의 일정한 값을 나타내었다.

키워드
임계하 균열성장
단조 하중
반복 하중
전단
인장
References
1
Ashby, M.F. and S.D. Hallam, 1986, The failure of brittle solids containing small cracks under compressive stress states, Acta Metal. 34.3, 497-510.
10.1016/0001-6160(86)90086-6
2
Atkinson, B.K., 1984, Subcritical crack growth in geological materials, J. Geophys. Res. 89.B6, 4,077-4,114.
10.1029/JB089iB06p04077
3
Atkinson, B.K. and P.C. Meredith, 1987, The theory of subcritical crack growth with applications to minerals and rocks. In: Fracture Mechanics of Rock, Academic Press, London, 111p.
10.1016/B978-0-12-066266-1.50009-0
4
Bobet, A., 1997, Fracture Coalescence in Rock Materials: Experimental Observations and Numerical Predictions. Sc. D. Thesis, Massachusetts Institute of Technology, Cambridge, U.S.A.
5
Charles, R.J., 1958, Static fatigue of glass, J. Appl. Phys. 29.11, 1,549-1,560.
10.1063/1.1722991
6
Cheon, D.S. and Y.B. Jung, 2017, Analysis of acoustic emission signals during long-term strength tests of brittle materials, Tunnel & Underground Space 27.3, 121-131.
7
Cox, S.J.D. and C.H. Scholz, 1988, Rupture initiation in shear fracture of rocks: an experimental study, J. Geophys. Res. 93, 4,920-4,938.
10.1029/JB093iB04p03307
8
Hashiba, K., S. Okubo, and K. Fukui, 2006, A new testing method for investigating the loading rate dependency of peak and residual rock strength, Int. J. Rock Mech. Min. Sci. 43, 894-904.
10.1016/j.ijrmms.2005.12.005
9
Ingraffea, A.R., 1987, Theory of crack initiation and propagation in rock. In: Fracture Mechanics of Rock, Academic Press, London, 76p.
10.1016/B978-0-12-066266-1.50008-9
10
Jung Y.B, D.S. Cheon, E.S. Park, C. Part, Y.S. Lee, C.W. Park, and B.H. Choi, 2014, Estimation of the characteristics of delayed failure and long-term strength of granite by brazilian disc test, Tunnel & Underground Space 24.1, 67-80.
10.7474/TUS.2014.24.1.067
11
Kemeny, J.M. and N.G.W. Cook, 1987, Crack models for the failure of rock under compression, Proc. 2nd Int. Conference Constitutive Laws for Engineering Materials, Theory and Applications, Tucson, Arizona, Vol. 1, 879-887.
12
Ko, T.Y., 2008, Subcritical crack growth under Mode I, II and III loading for Coconino sandstone. Ph.D. Thesis, University of Arizona, Tucson, U.S.A.
13
Ko, T.Y, J. Kemeny, and H.K. Moon, 2008, Determination of subcritical crack growth parameters using double torsion test, Journal of the Korean Society for Geosystem Engineering 45.6, 610-609.
14
Ko, T.Y. and J. Kemeny, 2011, Subcritical crack growth in rocks under shear loading. J. Geophys. Res. Solid Earth 116. B1, B01407.
10.1029/2010JB000846
15
Ko, T.Y. and J. Kemeny, 2013, Determination of the subcritical crack growth parameters in rocks using the constant stress-rate test. Int. J. Rock Mech. Min. Sci. 59, 166-178.
10.1016/j.ijrmms.2012.11.006
16
Ko, T.Y, J. Kemeny, and S.W. Jeon, 2017, Loading rate dependency of strength and fracture toughness of rocks, Proc. YSRM 2017 & NDRMGE 2017, Jeju, Korea.
17
Paris, P.C., and F. Erdogan, 1963, A critical analysis of crack propagation laws. J. Basic Engineering 85, 528-534.
10.1115/1.3656900
18
Swanson, P.L., 1984, Sub critical crack growth and other time and environment-dependent behavior in crustal rocks. J. Geophys. Res. 89, 8,015-8,036.
10.1029/JB089iB06p04137
Information
  • Publisher :Korean Society for Rock Mechanics and Rock Engineering
  • Publisher(Ko) :한국암반공학회
  • Journal Title :Tunnel and Underground Space
  • Journal Title(Ko) :터널과 지하공간
  • Volume : 29
  • No :2
  • Pages :124-134
  • Received Date : 2019-04-22
  • Revised Date : 2019-04-25
  • Accepted Date : 2019-04-26
  • DOI :https://doi.org/10.7474/TUS.2019.29.2.124
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