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 stability analysis for double deck tunnel branch geometry

복층터널 분기 기하구조에 따른 안정성 검토에 관한 연구

  • Park, Woo-Jeong (Geotechnical Department, Sambo Engineering Co., Ltd.) ;
  • Jang, Namju (Geotechnical Department, Sambo Engineering Co., Ltd.) ;
  • Kim, Kihwan (Geotechnical Department, Sambo Engineering Co., Ltd.) ;
  • Choi, Chang-rim (Geotechnical Department, Sambo Engineering Co., Ltd.)
  • 박우정 (삼보기술단 지반사업부) ;
  • 장남주 (삼보기술단 지반사업부) ;
  • 김기환 (삼보기술단 지반사업부) ;
  • 최창림 (삼보기술단 지반사업부)
  • Received : 2018.01.31
  • Accepted : 2018.02.27
  • Published : 2018.03.31
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Abstract

The tunnel can be planned to connect to underground roadway and surface road. The large tunnel and branch section are made when the ramp tunnel access to the main tunnel. In the branch section, stress concentration can be assigned and it can be very important for the stability of the tunnel. This study assessed the behavior of rock pillar in double deck tunnel diverging area by using a two dimensional numerical analysis. This study evaluated different safety factors according to pillar width and the ramp tunnel position in branch. By the assessment of the strength-stress ratio, tunnel pillar width is suggested in order to secure the safety factor 1.5.

도심지 터널에서 지하도로는 지상도로와의 연결을 위한 램프터널을 계획하게 되고 본선터널과 램프터널이 접속되는 구간에서 대단면 터널과 분기구간이 생성된다. 본선터널과 램프터널이 접속하는 근접구간에서 응력집중으로 터널의 안정성에 심각한 문제를 초래할 수 있다. 따라서 필라부의 안정성을 확보하는 것은 터널의 안정성을 좌우하는 매우 중요한 요소라 할 수 있다. 본 연구에서는 복층터널을 대상으로 본선터널, 분기부대단면 터널 단면을 계획하고, 분기부 암반 필라의 거동을 2차원 수치해석 방법으로 검토하였다. 양호한 지반조건인 암반 III등급에서 램프터널이 본선터널에 접속하는 방법을 달리하여 필라폭에 따른 지반 안정성을 평가하였으며, 안전율 1.5 이상을 확보할 수 있는 터널 필라폭을 제안하였다.

Keywords

References

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