Evaluation for Rock Cleavage Using Distribution of Microcrack Lengths

Abstract

핵심어: 쥬라기 화강암, 결, 확대사진, 길이-누적빈도 도표, 지수 직선, 미세균열의 모수 Abstract: Jurassic granite from Geochang was analysed with respect to the characteristics of the rock cleavage. The phases of distribution of microcracks were well evidenced from the enlarged photomicrographs(×6.7) of the thin section. In this study, the length -cumulative frequency diagrams were used for expressing the distribution characteristics of microcrack. The diagrams for the six directions were arranged in the magnitude of density(ρ). These diagrams show an order of H2 < H1 < G2 < G1 < R2 < R1 from the related chart. Among six diagrams, the diagram for hardway 2(H2) occupies the lowermost region on the left. On the contrary, the diagram for rift 1(R1) occupies the uppermost region on the right. Curve patterns of the two diagrams change from uniform to exponential distribution type in accordance with the increased density. The overall distribution characteristics of the diagrams were well evidenced from the magnitude of the exponent(λ) and length of line oa related to the exponential straight line. The magnitude of exponent governing the values of slope(θ) is inversely proportional to the values of microcrack parameters such as number(N), length(L) and density. On the contrary, length of line oa is directly proportional to the values of the above three parameters. Above microcrack parameters related to

Evaluation for Rock Cleavage Using Distribution of Microcrack Lengths and Spacings (1)

“…This type of correlation analysis is useful for evaluating the relative strength of rock cleavage and discriminating three quarrying planes. (Park, 2007) (Douglass and Voight, 1969;Thill et al, 1969;Peng and Johnson, 1972;Thill et al, 1973;Plumb et al, 1984) 그리고 국내의 연구사례 (Jang and Oh, 2001;Park et al, 2001Park et al, , 2004Park, 2007Park, , 2011Park, , 2015aPark, , 2015b)에서는 석영 및 장 석내 미세균열을 강조하고 있으며, 상대적인 분리성, 즉 리프트 > 그레인 > 하드웨이를 제시하고 있다. 이외 국내의 연구 사례 (Jang et al, 1998;Lee et al, 1999;Seo and Jeong, 1999;Seo et al, 2002;Park and Seo, 2003;Park, 2005;Chae and Seo, 2011;Kang et al, 2014) …”

Evaluation for Rock Cleavage Using Distribution of Microcrack Spacings (III)

“…특히 화강암(리프트, 그레인 및 하드웨 이)과 관련된 일부 연구사례 (Park et al, 2001(Park et al, , 2004Park, 2011;Freire-Lista and Fort, 2015;Park, 2015aPark, , 2016aPark, , 2016b (Park, 2016a(Park, , 2016b. Park et al, 2001Park et al, , 2004Park, 2007Park, , 2011Park, , 2015aPark, , 2015bPark, , 2016aPark, , 2016b. (Park, 2015b(Park, , 2016a(Park, , 2016b.…”

“…Park et al, 2001Park et al, , 2004Park, 2007Park, , 2011Park, , 2015aPark, , 2015bPark, , 2016aPark, , 2016b. (Park, 2015b(Park, , 2016a(Park, , 2016b. (Park, 2016a(Park, , 2016b.…”

“…(Park, 2016a(Park, , 2016b. (Park, 2015b), Reduction ratio: ([ (1)- (2)/(1)]×100, %). 3개 면, 3개 결의 순위의 종합 빈도수, 평균값, 중앙값, (평균값-중앙값) 및 밀도에 대한 3개 면별 평균 감소비율은 1 ≪ 3 < 2, 1 ≪ 2 < 3, 1 < 3 < 2, 1 < 2 < 3 및 1 ≪ 3 < 2의 순 그리고 3개 결별 평균 감소비율은 2 < 3 ≪ 1, 3…”

“…특히 (평균 간격 -중앙 간격) 및 평균 간격은 도표의 배열 순위에 대 한 윤곽의 사전 파악을 위한 근거가 될 수 있다 (Park, 2016a(Park, , 2016b. 한편 길이와 관련된 여섯 도표의 배 열성은 H2 < H1 < G2 < G1 < R2 < R1의 순이 다 (Park, 2015b). 3번 결 < 2번 결 < 1번 결의 순 그리고 (2) < (1)의 순으로 나타나며, 간격의 도표와 상호 역순의 상관성을 지닌다 (Fig.…”