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(사)한국터널지하공간학회

A study on the field tests and development of quantitative two-dimensional numerical analysis method for evaluation of effects of umbrella arch method

(사)한국터널지하공간학회 / (사)한국터널지하공간학회, (P)2233-8292; (E)2287-4747
2009, v.11 no.1, pp.57-70




Abstract

Considerable advance has been made on research on effect of steel pipe Umbrella Arch Method (UAM) and mechanical reinforcement mechanism through numerical analyses and experiments. Due to long analysis time of three-dimensional analysis and its complexity, un-quantitative two-dimensional analysis is dominantly used in the design and application, where equivalent material properties of UAM reinforced area and ground are used , For this reason, development of reasonable, theoretical, quantitative and easy to use design and analysis method is required. In this study, both field UAM tests and laboratory tests were performed in the residual soil to highly weathered rock; field tests to observe the range of reinforcement, and laboratory tests to investigate the change of material properties between prior to and after UAM reinforcement. It has been observed that the increase in material property of neighboring ground is negligible, and that only stiffness of steel pipe and cement column formed inside the steel pipe and the gap between steel pipe and borehole contributes to ground reinforcement. Based on these results and concept of Convergence Confinement Method (CCM), two dimensional axisymmetric analyses have been performed to obtain the longitudinal displacement profile (LDP) corresponding to arching effect of tunnel face, UAM effect and effect of supports. In addition, modified load distribution method in two dimensional plane-strain analysis has been suggested, in which effect of UAM is transformed to internal pressure and modified load distribution ratios are suggested. Comparison between the modified method and conventional method shows that larger displacement occur in the conventional method than that in the modified method although it may be different depending on ground condition, depth and size of tunnel, types of steel pipe and initial stress state. Consequently, it can be concluded that the effect of UAM as a beam in a longitudinal direction is not considered properly in the conventional method.

keywords
Effect of umbrella arch method, convergence confinement method, axisymmetric analysis, plane-strain condition, internal pressure, UAM 효과, 내공변위제어법, 축대칭 해석, 평면변형률 조건, 내압

Reference

1.

1. 김선홍, 문현구 (2002), “9Umbrella arch 공법의 보강효과 및 천단침하량 예측에 관한 연구”, 터널과 지하공간,Vol. 39, No. 3, pp. 259-267.

2.

2. 김창용, 배규진, 문현구, 최용기 (1998), “Umbrella Arch공법이 적용된 터널의 3차원 유한요소 해석에 관한 연구”, 터널과 지하공간, Vol. 8, No. 3, pp. 209-225.

3.

3. 박이근, 임종철 (2004), “강관다단 그라우팅공법(UAM)의 설계법 제안”, 한국지반공학회논문집, 제 20권 3호pp. 97-106.

4.

4. 배규진, 김창용, 문홍득, 홍성완 (1997), “Umbrella Arch공법에 의한 터널 천단부 보강시 주변지반의 거동에 관한 연구”, 터널과 지하공간, Vol. 7, No. 4, pp. 299-309.

5.

5. 장석부, 권승, 김기림, 허도학 (2002), “터널 막장보강을위한 합리적인 선진보강공법설계기법”, 한국터널공학회지, Vol. 4. No. 3, pp. 6-13.

6.

6. 차민웅, 이승도, 문현구 (2004), “ Umbrella Arch 공법이적용시 강관의 거동에 관한 수치해석적 연구”, 터널과지하공간, Vol. 14, No. 1, pp. 26-34.

7.

7. 최용기, 김창용, 한명훈, 황찬호 (1997), “연약지반 터널굴착시의 지반보강사례연구”, 97한국지반공학회 가을학술발표회 논문집, pp. 133-139.

8.

8. 한국터널공학회 (2007), “터널의 이론과 실무 - 도심지천층 및 근접터널”.

9.

9. Barisone, G., Pigorini, B. and Pelizza, S. (1982), “Umbrella Arch Method for Tunnelling in Difficult Conditions-Analysis of Italian Cases”, proc. 4th Congress of International Association of Wngineering Geology, New Delhi, Vol. 4,pp. 15-27.

10.

10. Carranza-Torres, C. and Fairhurst (2000), “Application of the Convergence-Confinement Method of Tunnel Design to Rock Masses That Satisfy the Hoek-Brown Failure Criterion”, Tunnelling and Underground Space Technology,Vol. 15, No. 2, pp. 187-213.

11.

11. Melbye, T. and Garshol, K.F. (2000), “Spayed shotcrete for rock support” Master Builders Technologies.

12.

12. Oreste, P., P. and Peila, D. (1998), “A New Theory for Steel Pipe Umbrella Design in Tunnelling”, Proc. of the World Tunnel Cong. 98 on Tunnels and Metropolises,Vol. 2, pp. 1033-1039.

13.

13. Pelizza, S. and Peila, D. (1993), “Soil and Rock Reinforcements in Tunnelling”, Tunnelling and Underground Space Technology, Vol. 8, No. 3, pp. 357-372.

14.

14. Pelizza, S., Peila, D. and Oreste, P., P. (1994(a)), “A New Approach for Ground Reinforcing Design in Tunnelling”,Tunnelling and Ground Conditions, Balkemma, pp.517-522.

15.

15. Pelizza, S., Corona, G., Garasso, F. and Raineri, R.(1994(b)), “Improvement of Stability Conditions for Half to Full Face Excavation in Difficult Ceotechnical Conditions”,Tunnelling and Ground Conditions, Balkemma,pp. 267-271.

(사)한국터널지하공간학회