터널과지하공간 (Tunnel and Underground Space)

  • 제30권3호
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  • Pages.226-241
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  • 2020
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  • 1225-1275(pISSN)
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  • 2287-1748(eISSN)
한국암반공학회 (Korean Society for Rock Mechanics and Rock Engineering)
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절리면의 방향, 절리선 길이 및 광주 형상비가 광주 강도에 미치는 영향 분석

The Change of Pillar Strength due to Joint Dip Angles, Total Trace Length and Width-to-Height ratio of a Pillar

  • 최지원 (서울대학교 에너지시스템공학부) ;
  • 이용기 (서울대학교 에너지시스템공학부) ;
  • 송재준 (서울대학교 에너지시스템공학부)
  • Choi, Ji-won (Department of Energy Systems Engineering, Seoul National University) ;
  • Lee, Yong-Ki (Department of Energy Systems Engineering, Seoul National University) ;
  • Song, Jae-Joon (Department of Energy Systems Engineering, Seoul National University)
  • 투고 : 2020.06.08
  • 심사 : 2020.06.25
  • 발행 : 2020.06.30
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초록

지하 광산 공동의 안전성은 광주의 강도와 밀접한 관계가 있다. 광주의 강도를 알고 있다면 광주의 위험성을 판단할 수 있고 그에 따른 적절한 조치를 취할 수 있다. 광주의 강도는 광주 내에 존재하는 불연속면의 특성과 광주의 형상에 영향을 받는다. 본 연구에서는 광주를 관통하는 불연속면과 광주의 종횡비, 광주 내부에 존재하는 소규모의 내포 절리에 따른 강도 변화를 PFC 3D를 이용하여 분석하였다. 그 결과, 광주의 강도는 불연속면의 경사각에 영향을 받으며, 광주의 폭이 넓어질수록 강도가 증가하고 내포 절리의 수가 증가할수록 강도가 감소함을 확인하였다. 내포 절리로 인해 광주 표면에 나타나는 절리선 길이의 총합과 광주 강도와의 관계를 지수 함수로 회귀한 결과, 두 인자 사이의 높은 상관계수를 얻었다. 따라서 하나의 절리군이 존재할 때, 지수 함수식을 통해 절리선 길이의 총합으로부터 광주의 강도를 예측할 수 있다. 마지막으로 경사각이 60°, 30°인 두 절리군이 존재할 때 절리선 길이의 총합으로부터 광주 강도를 추정할 수 있는 식을 제시하였다.

The stability of underground mine cavity is closely related with pillar strength. The vulnerability of pillars can be judged and reinforced if the pillar strength is known. The pillar strength is affected by characteristics of discontinuities and shape of a pillar. The change of pillar strength due to a discontinuity passing through the center of a pillar, width-to-height ratio of a pillar and small joints existing within a pillar was analyzed using PFC 3D. The result showed that the pillar strength is influenced by dip angle of a discontinuity and it increases as width-to-height ratio of a pillar increases. The pillar strength decreases as the number of contained joints increases. The relationship between total trace length observable from the pillar surface and the pillar strength was regressed with exponential function. The correlation coefficient of the regression was high enough so that pillar strength can be predicted using total trace length if a joint set exists in a pillar. Lastly, the method to estimate the strength of a pillar that includes two joint sets was proposed if the joint dip angles are 60°, 30°. The method also need total trace lengths of two joint sets.

키워드

참고문헌

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