Tunnel and Underground Space (터널과지하공간)

Korean Society for Rock Mechanics and Rock Engineering (한국암반공학회)
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Review on Rock-Mechanical Models and Numerical Analyses for the Evaluation on Mechanical Stability of Rockmass as a Natural Barriar

천연방벽 장기 안정성 평가를 위한 암반역학적 모델 고찰 및 수치해석 검토

  • Myung Kyu Song (Dept. of Earth Resources and Environmental Engineering, Hanyang University) ;
  • Tae Young Ko (Dept. of Energy and Resources Engineering, Kangwon National University) ;
  • Sean S. W., Lee (Dept. of Earth Resources and Environmental Engineering, Hanyang University) ;
  • Kunchai Lee (REX ENG) ;
  • Byungchan Kim (REX ENG,) ;
  • Jaehoon Jung (R&D Department, Hyundai E&C) ;
  • Yongjin Shin (R&D Department, Hyundai E&C)
  • 송명규 (한양대학교 자원환경공학과) ;
  • 고태영 (강원대학교 에너지자원.산업공학부) ;
  • 이승원 (한양대학교 자원환경공학과) ;
  • 이근채 (렉스이엔지) ;
  • 김병찬 (렉스이엔지) ;
  • 정재훈 (현대건설 기술연구원) ;
  • 신영진 (현대건설 기술연구원)
  • Received : 2023.11.23
  • Accepted : 2023.12.26
  • Published : 2023.12.31
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Abstract

Long-term safety over millennia is the top priority consideration in the construction of disposal sites. However, ensuring the mechanical stability of deep geological repositories for spent fuel, a.k.a. radwaste, disposal during construction and operation is also crucial for safe operation of the repository. Imposing restrictions or limitations on tunnel support and lining materials such as shotcrete, concrete, grouting, which might compromise the sealing performance of backfill and buffer materials which are essential elements for the long-term safety of disposal sites, presents a highly challenging task for rock engineers and tunnelling experts. In this study, as part of an extensive exploration to aid in the proper selection of disposal sites, the anticipation of constructing a deep geological repository at a depth of 500 meters in an unknown state has been carried out. Through a review of 2D and 3D numerical analyses, the study aimed to explore the range of properties that ensure stability. Preliminary findings identified the potential range of rock properties that secure the stability of central and disposal tunnels, while the stability of the vertical tunnel network was confirmed through 3D analysis, outlining fundamental rock conditions necessary for the construction of disposal sites.

수만년 이상의 기간동안의 장기 안전성을 확보하는 것이 처분장 건설에서의 최우선 조건이나, 건설 및 운영중 대심도 지하 사용후핵연료 처분장의 역학적 안정성 확보 역시 안전한 터널 공사 및 운영을 위해 필수적인 요소이다. 처분장의 장기 안전성에 중요한 요소인 벤트나이트 충전재 및 완충재의 차폐 성능을 저감시킬 가능성이 있는 숏크리트, 콘크리트, 그라우팅 등의 터널 지보공 및 차수공을 금지 내지는 제한하는 조건은 암반공학자 및 터널 기술자에게 매우 도전적인 과제로 판단된다. 본 연구에서는 처분장 부지 선정과정에서 올바른 처분장의 선정에 도움이 될 수 있는 대심도에 건설할 것으로 예상되는 처분장의 터널 네트워크, 처분 터널 및 처분공의 역학적 안정성을 확보하기 위한 제반 조건의 광범위한 탐색의 일환으로 지하 500 m 심도의 처분장을 무지보 상태로 건설할 경우 2차원 및 3차원 수치해석 검토를 통해 안정성의 확보 가능한 물성 범위를 탐색하고자 하였다. 예비 연구결과 처분장의 중앙터널과 처분터널 안정성 확보 가능 암반물성의 범위를 파악하였으며, 3차원 해석을 통해 수직구 주변 터널 네트워크의 안정성을 확인하여 처분장 건설을 위한 기초적인 암반 조건이 파악된 것으로 판단된다.

Keywords

Acknowledgement

본 연구는 산업통상자원부의 재원으로 사용후 핵연료 관리 핵심기술 개발사업단 및 산업부 한국에너지기술평가원의 지원을 받아 수행된 연구 사업의 일환으로 수행되었습니다(No. 2021040101003C). 이에 감사드립니다.

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