화강암에서 SR 시편의 파괴인성과 미세구조적인 특징
Characterization of Microstructures and Fracture Toughness of SR Specimen in Granitic Rocks
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초록
비교적 균질한 3가지 화강암이 암석의 미세구조적 특성과 파괴인성 사이의 관계를 조사하기 위하여 연구되었다. 광학 현미경 관찰로 분석된 광물입자의 장축과 미세균열의 방위에 의하여 파괴인성 및 초음파 속도의 변화를 보였다. 가장 작은 값을 나타내는 파괴인성은 인장응력 방향과 수직하게 발달된 광물입자의 장축 및 미세균열의 방향이 주결에 일치할 때로서 파괴가 연약면인 광물입자의 장축이나 미세균열의 우세방향에 평행하게 전달될 때이다. SR 시편으로 측정된 파괴인성값은 1.63~2.62 MPa m0.5의 변화를 보이며, 그 값들은 광물입자의 평균크기 및 미세균열의 평균길이와 관련된다.
Abstract
Three relatively homogeneous granitic rocks were studied to investigate the relationship between their microstructural properties and fracture toughness. Fracture toughness and ultrasonic velocity were varied with the orientation of mineral's long axis and microcrack, obtained from optical microscope. The lowest fracture toughness values are obtained, when the fracture propagates parallel to weakness planes which have the orientation of mineral's long axis and microcrack, in other words, when weakness planes develop perpendicular to the direction of tensile stress agrees with that of rift plane. The fracture toughness values, measured with the short rod method, varied from 1.63 to 2.62 MPa m0.5, and their values are related with the average grain size and average microcrack length.
참고문헌 (15)
- Atkinson, B. K., "Fracture mechanics of rock" (1987), Academic Press
- Whittaker, B. N., "Rock fracture mechanics in principles, design and application" (1992), Elsevier
- Nasseri, M. H. B., "Characterization of microstructures and fracture toughness in five granitic rocks", Int. J. of Rock Mech. & Min. Sci., 42, pp.450~460 (2005)
- Inoue, M., "Relation between uniaxial compressive strength and elastic wave velocity of soft rock", Porceedings of the int'l Symp. on Weak Rock, pp.9~13 (1981)
- D'Andrea, D. V., "Prediction of compressive strength from other rock properties", US Bureau of Mines Report of Investigations, 6702 (1965)
- King, M. S., "Experimental ultrasonic velocities and permeability for sandstones with aligned cracks", Int'l J. Rock Mech. Min. Sci., 32(2), pp.155~163 (1995)
- Gaviglio, P., "Longitudinal waves propagation in a limestone: the relationship between velocity and density", Rock Mech. Rock Eng., 22, pp.299~306 (1989)
- Yasar, E., "Correlating sound velocity with the density, compressive strength and Young's modulus of carbonate rocks", Int'l J. Rock Mech. Min. Sci., 41, pp.871~875 (2004)
- Sano, O., "Experimental determination of elastic constants of Oshima granite, Barre granite, and Chelmsford granite", J. Geophys. Res., 97, pp.3367~3379 (1992)
- Nasseri, M. H. B., "Fracture toughness anisotropy in granitic rocks", Int. J. of Rock Mech. & Min. Sci., 45, pp.167~193 (2008)
- Barker, L. M., "A simplied method for measuring plane strain fracture toughness", Eng. Fract. Mech., 9, pp.361~369 (1977)
- Ouchterlony, F., "Suggested method for determing the fracture toughness of rock", Int. J. of Rock Mech. & Min. Sci., 25, pp.71~96 (1988)
- Ouchterlony, F., "Fracture toughness testing of with core based specimens", Eng. Fract. Mech., 35, pp.351~366 (1990)
- Nasseri, M. H. B., "Coupled evolutions of fracture toughness and elastic wave velocities at high crack density in thermally treated Westerly granite", Int. J. of Rock Mech. & Min. Sci., 44, pp.601~616 (2007)
- Douglass, P. M., "Anisotropy of granite: a reflection of microscopic fabric", Geotechnique, 19, pp.376~398 (1969)