지질공학 (The Journal of Engineering Geology)

  • 제21권4호
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  • Pages.295-304
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  • 2011
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  • 1226-5268(pISSN)
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  • 2287-7169(eISSN)
대한지질공학회 (The Korean Society of Engineering Geology)
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음향방출기법을 이용한 KURT 화강암의 균열 발생 특성에 관한 실험적 연구

An Experimental Study on Crack Propagation in KURT Granite using Acoustic Emission

  • 투고 : 2011.09.14
  • 심사 : 2011.11.09
  • 발행 : 2011.12.30
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초록

방사성폐기물처분장 주변 암반의 수많은 불확실성을 이해하기 위해서는 무결암에서 발생하는 균열의 성장과 거동 분석은 필수이다. 이에 본 연구에서는 처분장과 유사한 지질적 구조적 특성을 지닌 한국원자력연구원 내에 위치한 지하처분연구시설에서 채취한 화강암 시료를 이용하여 균열의 성장과 이에 따른 손상도를 AE parameter와 모멘트텐서해석법을 이용하여 분석하였다. 시료의 균열개시 균열결합 균열손상응력은 최대강도의 0.45배, 0.73배, 0.84배인 것으로 나타났다. 모벤트텐서해석법을 이용한 결과 응력 초기에는 인장균열의 발달이 우세하였으나 응력 수준이 증가함에 따라 전단균열이 발달하였다. 또한 시료에 균열손상응력 이상의 응력이 가해지면 파괴면을 중심으로 불안정한 전단균열이 발생하였으며 이는 파괴에 직접적인 역할을 하는 것으로 해석되었다.

The first step in improving our understanding of uncertainties suclt as rock mass strength parameters and deformation modulus in rock masses around high-level radioactive waste disposal repositories, for improved safety, is to study the process of crack development in intact rock. Therefore, in this study, the fracture process and crack development were examined in samples of KURT granite taken from the KAERI Underground Research Tunnel (KURT), based on acoustic emission (AE) and moment tensor analysis. The results show that crack initiation, coalescence, and unstable crack occurred at rock uniaxial compressive strengths of 0.45, 0.73, and 0.84, respectively. In addition, moment tensor analysis indicated that during the early stage of loading, tensile cracks were predominant. With increasing applied stress, the number of shear cracks gradually increased. When the applied stress exceeded the stress level required for crack damage, unstable shear cracks which directly result in failure of the rock were generated along the failure plane.

키워드

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피인용 문헌

  1. 강원도 간성-현내 지역 화강암류 비탈면 안정성 검토 사례 연구 vol.22, pp.3, 2011, https://doi.org/10.9720/kseg.2012.3.331