Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
권호 표지

New Observational Design and Construction Method in Tunnels and Its Application to Very Large Cross Section Tunnel

터널의 신 정보화 설계시공법과 극대단면 터널에의 적용

  • Published : 2004.09.01
Download PDF
⟨ Previous Next ⟩

Abstract

The observational design and construction method in tunnels is becoming important recently. In many tunnels, enormous cost and time are consumed to cope with the failing or sliding of rock blocks, which could not be predicted because of the complexity of rock discontinuities. It is difficult to estimate the properties of rock masses before the construction. In this paper, a new observational design and construction method in tunnels are proposed, and then applied to the example of the very large cross section tunnel based on actual discontinuity information observed in situ. The items examined in developing a program for the new observational design and construction method are the following ones: generality, precision, high speed, and friendly usability. At the very large cross section tunnel, 7 key blocks were judged to be unstable because they could not be supported by standard supports. Supplementary supports were installed to these 7 key blocks before the excavation. It is possible to detect key blocks all along the tunnel exactly by using the numerical analysis program developed for the new observational design and construction method in the very large cross section tunnel. This computer simulation method with user-friendly interfaces can calculate not only the stability of key blocks but also the design of supplementary supports.

최근 터널의 정보화 설계시공이 중요시 되어지고 있다. 암반구조의 복잡성으로 인해 사전에 예측 할 수 없었던 암반의 붕락이 발생하여, 붕락대책에 막대한 비용과 시간을 낭비하는 사례가 많다. 암반 불연속면의 복잡성을 사전 조사 단계에서 충분히 파악하거나 대책을 수립하는 것은 어렵다. 본 논문에서는 터널의 신 정보화 설계시공법을 제안하고, 현장에서 관찰한 불연속면 정보를 근거로 하여 극대단면 터널에 적용했다. 터널의 신 정보화 설계시공법을 위한 수치해석 프로그램은 범용성, 정밀성, 신속성, 편리한 사용성을 검토하여 새롭게 개발되었다. 극대단면 터널에서는 표준지보에 의해 지지할 수 없는 불안정 키블럭이 7개 존재하는 것이 판명되었다. 7개의 키블럭에 대해서는 굴착전에 추가 지보를 실시했다. 극대단면 터널에 있어서, 터널의 신 정보화 설계시공법을 위해서 새롭게 개발한 수치해석 프로그램을 사용하여 정확한 키블럭 추출이 가능한 것을 검증하였다. 사용하기 쉬운 사용자 인터페이스를 가지고 있는 본 컴퓨터 시뮬레이션 기법은 키블럭의 안정성 계산뿐만 아니라 추가보강대책공의 설계도 가능하다.

Keywords

References

  1. Collaborative Research Group for the Granites around Lake Biwa (1982), Granitic masses around Lake Biwa, Southwest Japan On the granites in the Koga area, J. of The Geol. Soc. of Japan, Vol.88, No.4, pp.289-298 https://doi.org/10.5575/geosoc.88.289
  2. Goodman, R. E. and Shi, G. H. (1985), Block Theory and Its Application to Rock Engrg., Prentice-Hall
  3. Hwang, J.-Y., Ohnishi, Y. and Nishiyama, S. (2002), Key Block Analysis in Tunnel Construction for the Geological Disposal of High-Level Radioactive Waste, Proc. 2nd Japan-Korea Joint Seminar on Geoenv. Engrg., Japan, pp.61-68
  4. Hwang, J.-Y. (2003a), Stability Evaluation of Rock Blocks in Tunnels for Observational Method, Chapter 10, Chapter 11, Ph. D. Dissertation, Kyoto University, Kyoto, pp.225-268
  5. Hwang, J.-Y. and Ohnishi, Y. (2003b), New Mechanized Tunneling Method and Its Application to Large Tunnel, Proc. 4th Sym. on Mechanized Tunneling Techniques, KTA, pp.159-174
  6. Hwang, J.-Y., Ohnishi, Y. and Nishiyama, S. (2003c), Removability and Stability Analysis Method of Rock Blocks Considering Discontinuity Persistence in Tunnel Construction, Jour. of the KGS, KGS, pp.39-48
  7. Hwang, J.-Y., Sato, M. and Ohnishi, Y. (2004), Quick Evaluation Method for Discontinuity Properties by Vision Metrology for Observational Design and Construction Method in Tunnels, Proc. 33rd Symp. Rock Mechanics, JSCE, pp.187-192
  8. Kimura, K., Yoshioka, T., Imoto, N., Tanaka, S. Musashino, M. and Takahashi, Y. (1998), Geology of the Kyoto-Tohokubu district. With Geological Sheet Map at 1:50,000, Geol. Surv. Japan
  9. Miyamura, M., Yoahida, F., Yamada, N., Sato, T. and Sangawa, A. (1981), Geology of the Kameyama district, Quadrangle Series, Scale 1:50,000, Geol. Surv. Japan
  10. Ohnishi, Y., Nagano, K. and Fujikawa, T. (1985), Evaluation of Stability of Excavated Jointed Rock Mass by Block Theory, J. Geotech. Engrg., JSCE, No.364 / III-4, pp.209-218
  11. Ohnishi, Y. (1999), Survey, Analysis and Evaluation for Dis-continuous Rock Mass, Soil and Foundation, JGS, VoI.47-12, pp.61-62
  12. Ohnishi Y. (2002), Keynote Lecture: Numerical Methods and Tunneling, Proc. of the Fourth Int'l Summer Symp., JSCE, Kyoto, Japan, pp.1-21.