Tunnel and Underground Space (터널과지하공간)

Korean Society for Rock Mechanics and Rock Engineering (한국암반공학회)
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Cleavage Dependent Indirect Tensile Strength of Pocheon Granite Based on Experiments and DEM Simulation

포천화강암의 결에 따른 간접인장강도 특성에 대한 실험 및 개별요소 수치해석

  • 장리 (한국건설기술연구원 지반연구소) ;
  • 멜빈 디아즈 (과학기술연합대학원대학교(UST) 지반신공간공학과) ;
  • 정성규 (과학기술연합대학원대학교(UST) 지반신공간공학과) ;
  • 김광염
  • Received : 2016.08.16
  • Accepted : 2016.08.26
  • Published : 2016.08.31
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Abstract

The purpose of this study is to investigate the influence of cleavages on indirect tensile strength (ITS) of the granite. Brazilian disc tests and ring tests with three different hole sizes were performed. 2D DEM (Discrete Element Method) simulation was employed to further understand the failure process during the tests and the mechanism behind. Results show that ITS decreases across hardway, grain and rift cleavage. Measured average ITS from ring tests is about 2.5 ~ 6.4 times of those measured from Brazilian disc tests, and it decreases with increasing ratio of diameters of inner hole and specimen. Failure pattern in ring tests is influenced by both hole size and relative positions of cleavages parallel and perpendicular to the loading direction.

본 연구는 화강암에 존재하는 결 이방성이 간접인장강도에 미치는 영향을 평가하였다. 표준 간접인장시험 및 3개의 서로다른 중공 크기에 대한 중공 간접인장시험을 수행하였다. 2차원 개별요소 수치해석을 통해 간접인장시험에서의 파괴 과정 및 메커니즘을 고찰하였다. 간접인장강도는 화강암의 결에 따라 하드웨이, 그레인, 리프트 면의 순으로 감소하였다. 중공 간접인장강도는 일반 간접인장강도에 비해 2.5~6.4배 정도 크게 나타났으며, 중공 크기가 클수록 크게 나타났다. 중공 시편에 대한 간접인장 파괴 유형은 중공 크기 및 결과 하중방향 각도에 영향을 받는 것으로 나타났다.

Keywords

References

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