The Journal of Engineering Geology (지질공학)

The Korean Society of Engineering Geology (대한지질공학회)
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Experimental Study on the Deformation and Failure Behavior of Tono Granite

토노(Tono) 화강암의 변형 및 파괴거동에 관한 실험적 연구

  • Choi, Jung-Hae (Geologic Environment Division, Korea Institute of Geoscience and Mineral Resources) ;
  • Chae, Byung-Gon (Geologic Environment Division, Korea Institute of Geoscience and Mineral Resources)
  • 최정해 (한국지질자원연구원 지구환경연구본부) ;
  • 채병곤 (한국지질자원연구원 지구환경연구본부)
  • Received : 2012.03.19
  • Accepted : 2012.04.24
  • Published : 2012.06.30
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Abstract

The nature of surface deformation of Tono granite was investigated using a confocal laser scanning microscope (CLSM) under water-saturated stress relaxation conditions. A new apparatus was developed for this experiment, enabling continuous measurements of stress-strain and simultaneous observations of surface deformation by CLSM. The amounts of grain contact deformation and intra-granular surface deformation were calculated using a finite element method. The results reveal that intense grain contact deformation and intra-granular surface deformation occurred during the period of stress relaxation, and that the intensity of this deformation increased with increasing applied stress. Finite element method (FEM) results show that the strain of grain boundary was greater than strain of inter-granular surface. Contour maps of these local strains were compiled for individual grains and their boundaries, revealing intense deformation at the boundaries between biotite and quartz under compressional stress. This result was a consequence of the mechano-chemical effect of biotite and quartz minerals. Biotite in granite has a layered structure of iron-magnesium-aluminum silicate sheets that are weakly bonded together by layers of potassium ions. In contrast, quartz occurs as stable spherical grains.

본 연구에서는 응력완화실험을 통한 포화상태에서의 토노(Tono) 화강암의 표면변형에 대한 연구를 수행하였다. 본 실험을 위해서 실험이 진행되는 동안 실시간으로 다초첨 레이져 스캔 현미경(Confocal Laser Scanning Microscope, CLSM)으로 관찰이 가능하고 변위 및 응력에 대한 데이터 취득이 가능한 장치를 고안하였다. 광물내의 변형 및 광물경계부에서의 변형은 유한요소해석 방법을 사용하여 계산하였다. 그 결과 응력완화실험 중에는 광물 내부와 광물 경계부 모두에서 활발한 변형을 보이는 것이 관찰되었으며 이는 가해지는 응력이 높아질수록 더욱 커진다는 사실을 확인하였다. 또한 유한요소 해석의 결과는 광물내의 변화보다는 압축력에 의해서 발생되는 광물경계부에서의 변화가 더욱 크다는 것을 설명한다. 이를 도식화시켜 표현해보면 화강암 내부에서 광물 경계부의 변형이 광물 내부의 변형보다 크게 나타난다는 것을 쉽게 관찰 할 수 있다. 이는 흑운모와 석영의 물리화학적 특성에 기인된다고 사료된다. 즉 석영은 안정된 구체를 보이는 반면에 흑운모는 층상형태로 약한 결합구조를 보이고 있기 때문으로 판단된다.

Keywords

References

  1. 서용석, 2000, 화강암의 응력완화현상에 관한 수침삼축시험, 지질공학, 10, 217-223.
  2. Balke, P., De Hosson, J.Th.M., 2001, Orientation imaging microscopic observations of in situ deformed ultra low carbon steel, Scripta Materialia, 44, 461-466. https://doi.org/10.1016/S1359-6462(00)00632-1
  3. Brinck, A., Engelke, C., Kopmann, W., and Neuhauser, H., 2001, Structure and development of slip lines during plastic deformation of the intermetallic phases Fe3Al and CuZn, Materials Science and Engineering, A239-240, 180-187.
  4. Chandrasekaran, D., and Nygard, M., 2003, A study of the surface deformation behaviour at grain boundaries in an ultra-low-carbon steel, Acta Materialia, 51, 5375-5384. https://doi.org/10.1016/S1359-6454(03)00394-X
  5. Choi, J.H., Anwar, A.H.M.F., and Ichikawa, Y., 2008, Observation of time-dependent local deformation of crystalline rocks using a confocal laser scanning microscope, International Journal of Rock Mechanics & Mining Sciences, 45, 431-441. https://doi.org/10.1016/j.ijrmms.2007.07.004
  6. Fredrich, J.T., 1999, 3D imaging of porous media using laser scanning confocal microscopy with application to microscale transport processes. Physics and Chemistry of the Earth (A), 24(7), 551-561. https://doi.org/10.1016/S1464-1895(99)00079-4
  7. Ichikawa, Y., 1990, Introductions of finite element method in geomechanics, Nikka-Giren Pub, 18-145 [in Japanese].
  8. Man, J., Obrtlik, K., Blochwitz, C., and Polak, J., 2002, Atomic force microscopy of surface relief in individual grains of fatigued 316L austenitic stainless steel, Acta Materialia, 50(15), 3767-3780. https://doi.org/10.1016/S1359-6454(02)00167-2
  9. Passchier, C.W., and Trouw, R.A.J., 1996, Microtectonics, Heidelberg, Berlin, Springer, 92-110.
  10. Seo, Y., 1999, Damage process in granite: experimental observation, molecular dynamics simulation and its homogenization analysis, PhD thesis, Department of Geotech and Environ Eng. Nagoya University, Japan, pp. 147.
  11. Seo, Y., Seiki, T., and Ichikawa, Y., 1999, Crack generation and propagation during stress relaxation of crystalline rock under water-saturated uniaxial condition, Journal of the Society of Materials Science Japan, 48(11), 1255-1262 [in Japanese]. https://doi.org/10.2472/jsms.48.1255
  12. Vinogradov, A., Hashimoto, S., Patlan, V., and Kitagawa, K., 2001, Atomic force microscopic study on surface morphology of ultra-fine grained materials after tensile testing, Materials Science and Engineering, A319-321, 862-866.

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