All Issue

2009 Vol.11, Issue 3 Preview Page
A study on the asperity degradation of rock joint surfaces using rock-like material specimens

유사 암석 시편을 사용한 암석 절리면 돌출부 손상 연구

Eun-Soo Hong1
,
Tae-Hyuk Kwon2
,
Gye-Chun Cho3*
홍 은수1
,
권 태혁2
,
조 계춘3*
1한국과학기술원 건설 및 환경공학과 연구교수
2한국과학기술원 건설 및 환경공학과 박사후 연구원
3한국과학기술원 건설 및 환경공학과 교수
*교신저자. *Corresponding Author. 
30 September 2009. pp. 303-314
PDF XML Citation
Abstract

Image analyses for sheared joint specimens are performed to study asperity degradation characteristics with respect to the roughness mobilization of rock joints. Four different types of joint specimens, which are made of high-strength gypsum materials, are prepared by replicating the three-dimensional roughness of rock joints. About twenty jointed rock shear tests are performed at various normal stress levels. The characteristic and scale of asperity degradation on the sheared joint specimens are analyzed using the digital image analysis technique. The results show that the asperity degradation characteristic mainly depends on the normal stress level and can be defined by asperity failure and wear. The asperity degradation develops significantly around the peak shear displacement and the average amount of degraded asperities remains constant with further displacement because of new degradation of small scale asperities. The shear strength results using high-strength gypsum materials can not fully represent physical properties of each mineral particles of asperities on the natural rock joint surface. However the results of this quantitative estimation for the relationship between the peak shear displacement and the asperity degradation suggest that the characterization of asperity degradation provides an important insight into mechanical characteristics and shear models of rock joints.

Keywords
Image analysis
joint shear test
degradation
roughness mobilization

암석 절리면의 거칠기의 발현에 따른 돌출부의 손상 특성을 연구하기 위해 전단시험 한 절리면 시편에 대한 이미지 분석을 수행하였다. 동일한 절리면에 대한 반복적인 시험에는 복제 시편을 사용한 모델시험이 가장 적합하였으므로 암석 절리면으로부터 각기 다른 4종류의 3차원 거칠기를 복제하고, 고강도 석고를 사용한 시편을 제작하였다. 연직응력 수준을 변화시키며 총 20여회의 전단시험을 실시하였으며, 전단된 시편의 디지털 사진의 이미지 분석을 통하여 손상된 거칠기의 국지적 양상과 규모를 분석하였다. 분석 결과 거칠기의 손상 특성은 연직응력의 수준에 크게 의존하며, 돌출부의 파괴와 마모로 규정할 수 있는 것으로 나타났다. 돌출부 손상은 첨두 전단변위에서 가장 많이 발생하며, 변위가 증가하면 작은 돌출부들이 새롭게 손상되어 평균적인 돌출부의 손상 규모는 일정한 것으로 나타났다. 고강도 석고를 사용한 전단시험 결과에 자연 암석절리의 돌출부를 구성하는 광물입자의 물리적 특성이 완전하게 반영될 수는 없다. 그러나 첨두 전단변위와 돌출부 손상과의 상관관계에 대한 정량적 연구 결과는 돌출부 손상 특성의 파악이 암석 절리면 역학적 특성과 전단모델의 연구에 매우 중요한 수단이 될 수 있음을 보여준다.

키워드
거칠기 발현
돌출부 손상
이미지 분석
절리면 전단시험
References
1
1.이승도 (2002), “거칠기가 절리의 전단거동 및 투수성에 미치는 영향에 관한 연구”, 터널과 지하공간, 한국암반공학회, 제12권, 제4호, pp. 312-320.
2
2.이승우, 송재준 (2006), “무결함 재료의 크기에 따른 강도와 탄성계수의 변화에 대한 연구”, 터널기술, 한국터널공학회 논문집, 제8권, 제3호, pp. 205-217.
3
3.홍은수, 남석우, 이인모 (2005), “암석 절리면 거칠기의 정량화에 대한 연구 (I) - 문제점의 규명 -”, 터널기술, 한국터널공학회 논문집, 제7권, 제4호, pp. 269-283.
4
4.홍은수, 조계춘, 권태혁, 이인모 (2006), “암석 절리면 거칠기의 정량화에 대한 연구 (II) - 거칠기의 구분과 강도식의 제안 -”, 터널기술, 한국터널공학회 논문집, 제8권, 제2호, pp. 183-196.
5
5.Archard, J.F. (1957), “Elastic deformation and the laws of friction”, Proc. R. Soc. London, Ser. A, pp. 190-205.
6
6.Barton, N.R. (1973), “Review of a new shear-strength criterion for rock joints”, Engrg. Geol., Vol. 7, pp. 287-332.
7
7.Bandis, S.C., Lumsden, A.C. and Barton, N.R. (1981), “Experimental studies of scale effects on the shear behaviour of rock joints”, Int. J. Rock Mech. Min. Sci. Geomech. Abstr., Vol. 18, No. 1, pp. 1-21.
8
8.Barton, N.R. and Choubey, V. (1977), “The shear strength of rock joints in theory and practice”, Rock Mechanics, Vol. 10, pp. 1-54.
9
9.Bhushan, B. (2002), Introduction to tribology, John Wiley & Sons Inc., New York.
10
10.Borri-Brunetto, M., Carpinteri, A. and Chiaia, B. (1999), “Scaling phenomena due to fractal contact in concrete and rock fractures”, International Journal of Fracture, Vol. 95, pp. 221-238.
11
11.Brown, S.R. and Scholz, C.H. (1986), “Closure of rock joints”, Journal of Geophysical Research, Vol. 91, pp. 4939-4948.
12
12.Carr, J. R. and Warriner, J. B. (1989), “Relationship between the fractal dimension and joint roughness coefficient”, Bull. Assoc. Engrg. Geol., Vol. 26, pp. 253-264.
13
13.Chiaia, B. (2002), “On the sliding instabilities at rough surfaces”, Journal of the Mechanics and Physics of Solids, Vol. 50, pp. 895–924.
14
14.Gentier, S., Riss, J., Archambault, G., Flamand, R. and Hopkins, D. (1999), “Influence of fracture geometry on shear behavior”, Int. J. Rock. Mech. Min. Sci. Vol. 37, pp. 161-174.
15
15.Haberfield, C.M. and Johnston, I.W. (1994), “A Mechanically- based model for rough rock joints”, Int. J. Rock Mech. Min. Sci. Geomech. Abstr., Vol. 31, No. 4, pp. 279-292.
16
16.Hong, E.S., Lee, I.M. and Lee, J.S. (2006), “Measure-ment of rock joint roughness by 3D scanner”, Geotechnical Testing Journal, Vol. 29, No. 6, pp. 482-489.
17
17.Hong, E.S., Lee, J.S. and Lee, I.M. (2008), “Underesti-mation of the roughness in rough rock joint”, International Journal for Numerical and Analytical methods in Geo-mechanics, Vol. 32, pp. 1385-1403.
18
18.Hsu, S.M, Klaus, E.E. and Chang, H.S. (1988), “A mechano- chemical destructive model for wear under mixed lubrication conditions”, Wear, Vol. 128, pp. 307-323.
19
19.ISRM (1981), “Suggested method for the quantitative description of discontinuities in rock masse”, Rock Cha-racterization Testing and Monitoring, Pergamon press, Oxford, pp. 3-52.
20
20.Jaeger, J.C. (1971), “Friction of rocks and stability of rock slopes”, Geotechnique, Vol. 21 No. 2, pp. 97-134.
21
21.Karpenko, Y.A. and Akay, A. (2001), “A numerical model of friction between rough surfaces”, Tribology Int. Vol. 34, pp. 531-545.
22
22.Kulatilake, P.H.S.W., Shou, G. and Huang, T.H. (1995), “Spectral-based peak-shear-strength criterion for rock joints”, J. Geotech. Engrg., pp. 789-796.
23
23.Lam, T.S.K. and Johnstone, I.W. (1989), “Shear behavior of regular triangular concrete/rock joints evaluation”, J. Geotech. Engrg., ASCE, Vol. 115, No. 5, pp. 728-740.
24
24.Maerz, N.H., Franklin, J.A., and Bennett, C.P. (1990), “Joint roughness measurement using shadow profilometry”, Int. J. Rock Mech. Min. Sci. Geomech. Abstr., Vol. 27, pp. 329-343.
25
25.Misra, A. (2002), “Effect of asperity damage on shear behavior of single fracture”, Engineering Fracture Mechanics, Vol. 69, pp. 1997-2014.
26
26.Poon, C.Y. and Sayles, R.S. (1992), “The classification of rough surface contacts in relation to tribology”, J. Phys. D: Appl. Phys., Vol. 25, pp. A249-A256.
27
27.Reeves, M.J. (1985), “Rock surface roughness and frictional strength”, Int. J. Rock Mech. Min. Sci. Geomech. Abstr., Vol. 22, No. 6, pp. 429-442.
28
28.Seidel, J.P. and Haberfield, C.M. (2002), “A theoretical model for rock joints subjected to constant normal stiffness direct shear”, Int. J. Rock Mech. Min. Sci., Vol. 39, pp. 539-553.
29
29.Suh, N.P. and Sin, H.C. (1981), “The genesis of friction”, Wear, Vol. 69, pp. 91-114.
30
30.Tse, R. and Cruden, D.M. (1979), “Estimating joint roughness coefficients”, Int. J. Rock Mech. Min. Sci. Geomech. Abstr., Vol. 16, pp. 303-307.
31
31.Wang, W. and Scholz, C.H. (1993), “Scaling of constitutive parameters of friction for fractal surfaces”, Int. J. Rock Mech. Min. Sci. & Geomech. Abstr., Vol. 30, No. 7, pp. 1359-1365.
32
32.Yang, Z.Y., Di, C.C. and Yen, K.C. (2001), “The effect of asperity order on the roughness of rock joints. International Journal of Rock Mechanics and Mining Sciences”, Vol. 38, pp. 745-752.
33
33.Xie, H., Wang, J. and Xie, W. (1997), “Fractal effects of surface roughness on the mechanical behavior of rock joints”, Chaos, Solitons & Fractals, Vol. 8, No. 2, pp. 221-252.
Information
  • Publisher :Korean Tunneling and Underground Space Association
  • Publisher(Ko) :한국터널지하공간학회
  • Journal Title :Journal of Korean Tunnelling and Underground Space Association
  • Journal Title(Ko) :한국터널지하공간학회 논문집
  • Volume : 11
  • No :3
  • Pages :303-314
  • Received Date : 2009-07-03
  • Revised Date : 2009-07-20
  • Accepted Date : 2009-07-24
Journal Informaiton Journal of Korean Tunnelling and Underground Space Association Journal of Korean Tunnelling and Underground Space Association
Online Submission & Review System
  • NRF
  • KOFST
  • KISTI Current Status
  • KISTI Cited-by
  • crosscheck
  • orcid
  • open access
  • ccl
Journal Informaiton Journal Informaiton - close