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

Korean Tunnelling and Underground Space Association (한국터널지하공간학회)
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The behavior of tunnel and ground according to the loading of building construction on the ground

터널 상부 지반에 시공되는 건물 하중에 따른 터널 및 주변지반의 거동

  • Cha, Seok-Kyu (Dept. of Civil System Engineering, Ajou University) ;
  • Lee, Sang Duk (Dept. of Civil System Engineering, Ajou University)
  • 차석규 (아주대학교 대학원 건설시스템공학과) ;
  • 이상덕 (아주대학교 건설시스템공학과)
  • Received : 2018.05.10
  • Accepted : 2018.06.21
  • Published : 2018.07.31
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Abstract

Recently, the construction of the urban area has been rapidly increasing, and the excavation work of the ground has been frequently performed at the upper part of the existing underground structure. Especially, when the structure is constructed after the excavation of the ground, the loading and unloading process is repeated in the lower ground of the excavation so that it can affect existing underground structures. Therefore, in order to maintain the stability of the existing underground structure due to the excavation of the ground, it is necessary to accurately grasp the influence of the excavation and the structure load in the adjoining part. In this study, the effects of the ground excavation and the new structure load on the existing tunnel were investigated by large - scale experiment and numerical analysis. For this purpose, a large model tester with a size reduced to 1/5 of the actual size was constructed, and model tests and numerical analyzes were carried out to investigate the effects of the excavation of the body ground by maintaining the distance between the excavation floor and the tunnel ceiling constant, The impacts were identified. As a result of the study, it was confirmed that the deeper the excavation depth, the larger the influence on the existing tunnel. At the same distance, it was confirmed that the tunnel displacement increased with the increase of the building load, and the ground stress increased up to 2.4 times. From this result, it was confirmed that the effect of the increase of the underground stress on the existing tunnel is affected by the increase of the building load, and the influence of the underground stress is decreased from the new load width above 3.0D.

최근 도심지에서 기존터널 상부에 구조물을 신설하는 경우가 증가하고 있다. 특히 지반굴착 후 구조물이 시공되는 경우 굴착 저면 하부 지반 내에서는 하중 제하, 재하 과정이 반복되므로 기존 터널에 영향을 미칠 수 있다. 따라서 지반굴착으로 인한 기존 터널의 안정을 유지하기 위해서는 인접부에서의 굴착 및 구조물 하중에 의한 영향을 정확히 파악하여야 한다. 본 연구에서는 기존터널 상부지반 굴착 및 신설 구조물로 인한 하중이 기존터널에 미치는 영향을 대형 모형시험과 수치해석으로 통하여 파악하였다. 이를 위해 실제 크기의 1/5로 축소한 모형시험과 수치해석을 수행하여 굴착저면과 터널 천단 간의 거리를 일정하게 유지하고 지반굴착, 구조물 하중의 폭을 변화하여 그에 따른 영향을 파악하였다. 연구 결과, 동일 하중 크기에 대하여 굴착 깊이가 깊어져 굴착 저면과 기존터널이 가까울수록 더 큰 영향이 작용하는 것을 확인하였다. 동일 이격 거리에서 기존터널에 영향은 건물하중 폭 증가에 따라 터널 내공변위가 증가하는 것을 확인하였고, 지중응력은 최대 2.4배까지 증가하는 것을 확인하였다. 이로부터 건물하중 폭이 증가하면 지중응력의 증가 영향으로 기존 터널에 영향을 주는 것을 확인하였고, 기존터널을 중심으로 신규하중의 재하 폭이 터널직경의 3배 이상으로 이격되면 지중응력의 영향이 감소하는 것을 확인하였다.

Keywords

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