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A study on the effect of support structure of steel rib in partitioning excavation of tunnel

터널 상·하반 분할 굴착 시 강지보재 지지구조 효과에 대한 연구

  • Kim, Ki-Hyun (DMEC Co., Ltd.) ;
  • Kim, Yeon-Deok (Dept. of Civil Engineering, Hoseo University) ;
  • Hwang, Beoung-Hyeon (Dept. of Civil Engineering, Hoseo University) ;
  • Choi, Yong-Kyu (Dept. of Civil Engineering, Kyungsung University) ;
  • Kim, Sang-Hwan (Dept. of Civil Engineering, Hoseo University)
  • 김기현 (동명기술공단) ;
  • 김연덕 (호서대학교 토목공학과) ;
  • 황병현 (호서대학교 토목공학과) ;
  • 최용규 (경성대학교 토목공학과) ;
  • 김상환 (호서대학교 토목공학과)
  • Received : 2020.07.27
  • Accepted : 2020.08.18
  • Published : 2020.09.30

Abstract

This paper is the result of the study on the effect of the support structure of the tunnel steel rib. In tunnel excavation, the top and bottom half excavation methods result in subsidence of steel rib reinforcement due to insufficient support of steel rib reinforcement when the ground is poor after excavation. The foundation of the steel rib installed in the upper half excavates the bottom part of the base, causing the subsidence to occur due to various effects such as internal load and lateral pressure. As a result, the tunnel is difficult to maintain and its safety is problematic. To solve these problems, steel rib support structures have been developed. For the purpose of verification, the behavior of the supporting structure is verified by model experiments reduced to shotcrete and steel rib material similarity, the numerical analysis of ΔP and ΔP generated by bottom excavation by Terzaghi theoretical equation. As a result, it was found that the support structure of 20.100~198.423 kN is required for the 10~40 m section of the depth for each soil of weathered soil~soft rock. In addition, as a result of the reduced model experiment, a fixed level of 50% steel rib deposit of steel rib support structure was installed. The study shows that the installation of steel rib support structures will compensate for uncertainties and various problems during construction. It is also thought that the installation of steel rib support structure will have many effects such as stability, economy, and air reduction.

References

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