Journal of Korean Tunnelling and Underground Space Association (한국터널지하공간학회 논문집)

Korean Tunnelling and Underground Space Association (한국터널지하공간학회)
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A study on the effect of ground conditions of room and pillar method on pillar and room strain

격자형 지하공간의 지반조건이 암주와 룸 변형률에 미치는 영향에 대한 연구

  • Ham, Hyeon Su (R&D, ESCO Consultant & Engineers Company) ;
  • Kim, Yong Kyu (R&D, ESCO Consultant & Engineers Company) ;
  • Park, Chi Myeon (ESCO Consultant & Engineers Company) ;
  • Lee, Chul Ho (Dept. of Geotechnical Engineering Research, Korea Institute of Civil Engineering and Building Technology) ;
  • Kim, YoungSeok (Dept. of Infrastructure Safety Research, Korea Institute of Civil Engineering and Building Technology)
  • 함현수 (에스코컨설턴트 기술연구소) ;
  • 김용규 (에스코컨설턴트 기술연구소) ;
  • 박치면 (에스코컨설턴트) ;
  • 이철호 (한국건설기술연구원 지반연구본부) ;
  • 김영석 (한국건설기술연구원 인프로안전연구본부)
  • Received : 2021.10.25
  • Accepted : 2021.11.11
  • Published : 2021.11.30
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Abstract

Room and Pillar method is an underground facility construction method that maximizes the strength of the in-situ ground. In order to secure the safety of the underground space, it is necessary to secure the safety of the room actually used in addition to the safety of pillar of the room and Pillar method. In this study, the evaluation method for the safety of the room and rock pillar in the room and pillar method was studied through numerical analysis. Numerical analysis was performed for a total of 125 cases using ground conditions, pillar width, and room width as parameters, and the results were derived. As for the safety factor of the pillar, it was confirmed that the safety factor increased when the strength of the ground increased, and it was confirmed that the increment in the safety factor decreased when the width of the pillar was widened. The room strain was evaluated by applying the Critical strain. As the width of the pillar became narrower, the Critical strain was higher, and as the width of the room became smaller, the Critical strain was smaller. As a result of the correlation analysis between the safety factor of the pillar and the room strain, it was possible to derive the upper limit of the room strain that can secure the standard safety factor of the pillar according to the width of the pillar. It is judged that the results derived from this study can be used as a guideline to secure the safety of the room when the actual design is performed in consideration of the ground conditions and room width.

격자형 지하공간 공법은 원지반의 강도를 최대한 활용하는 지하공간 굴착 공법이다. 격자형 지하공간의 안전성을 확보하기 위해서는 암주에 대한 안전성뿐만 아니라 실제 사용되는 공간(Room)에 대한 안전성 또한 확보되어야 하므로 암주와 동시에 공간(Room)에 대한 안정성이 평가되어야 하나, 이에 대한 연구는 미흡한 실정이다. 본 연구에서는 수치해석을 통해 격자형 지하공간의 룸(Room)과 암주 안전성에 대한 평가방안을 연구하였다. 지반조건, 암주 폭, 룸 폭을 매개변수로 한 총 125가지 경우의 수치해석을 수행하여 암주의 안전율은 지반의 강도가 증가할 경우 안전율이 증가하는 것을 확인하였고, 암주의 폭이 넓어질 경우는 안전율 증가 폭이 감소하는 것을 확인하였다. 룸 변형률은 한계변형률을 적용하여 평가하였으며, 암주의 폭이 좁아질수록 높게 나타나고, 룸의 폭이 좁아질수록 변형률이 작게 발생하였다. 암주 안전율과 룸 변형률에 대한 상관관계 분석 결과 암주 폭에 따라 암주의 기준 안전율 이상을 확보할 수 있는 룸 변형률의 상한값을 도출 할 수 있었다. 본 연구에서 도출된 결과는 지반조건, 룸 폭 등을 고려하여 실제 설계를 수행할 경우 룸의 안전성을 확보 할 수 있는 가이드라인으로 활용 될 수 있을 것으로 판단된다.

Keywords

Acknowledgement

본 연구는 국토교통부 국토교통과학기술진흥원 '지하 공간 활용 도시기반 복합플랜트 실증연구 사업'의 '환경 기초 복합플랜트 지하공간 활용 기술(20UGCP-157962-02)'과제에 의해 수행되었습니다.

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