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

Korean Tunnelling and Underground Space Association (한국터널지하공간학회)
권호 표지
DOI QR코드

DOI QR Code

Variation of time-dependent convection beat transfer coefficients in beat transfer analysis at various initial beating rates of tunnel fire scenarios

요소제거모델을 활용한 열전달해석에서 터널 화재이력곡선의 초기가열구배에 따른 대류열전달계수의 변화

  • 최순욱 (한국건설기술연구원 기반시설연구본부 지반연구실, 연세대학교 사회환경시스템공학부 대학원) ;
  • 장수호 (한국건설기술연구원 기반시설연구본부 지반연구실) ;
  • 이춘환 (연세대학교 사회환경시스템공학부) ;
  • 안성율 (사이텍이앤씨)
  • Received : 2010.02.22
  • Accepted : 2010.04.26
  • Published : 2010.05.31
Download PDF
⟨ Previous Next ⟩

Abstract

The initial heating rate is well known as one of the most influencing factors on the occurrence of spalling and the loss of strength in concrete after fire initiation. In this study, a series of fire tests were carried out at different initial heating rates to find out its effects on the deterioration of tunnel structural members. Heat transfer analyses combined with an element elimination model were also carried out to verify its applicability in the same conditions as the fire tests. Moreover, the convection heat transfer coefficients compatible with fire test results were derived from parametric studies. In this course, their time-dependent variations were also analyzed at different initial heating rates. Finally, a numerical formula to estimate the heat transfer coefficients at the various initial heating rates was proposed by the interpolation of the results of numerical analyses.

본 연구에서는 화재에 의한 콘크리트의 단면손실과 역학적 특성을 저하하는 주요 요인 가운데 온도증가율, 즉 초기가열구배를 변화시키면서 모의화재실험을 수행하였다. 그리고 수행된 모의화재실험에서 관찰된 단면손실을 모사하기 위하여 요소제거모델을 활용한 유한요소해석법에 의해 열전달해석을 수행하였다. 이때 모의화재실험결과와 수치해석결과가 가장 일치하는 대류열전달계수를 반복적인 해석과정을 통해 도출하였다 이상의 과정으로부터 얻어진 초기가열구배에 따른 대류열전달계수의 변화를 조사한 결과, 각 초기가열구배별 대류열전달계수의 변화는 분수함수 형태로 근사시킬 수 있었다. 최종적으로 모의화재실험으로부터 도출된 초기가열구배별 대류열전달계수의 변화 결과를 내삽하여 다양한 초기가열구배에 따른 화재경과시간별 대류열전달계수의 변화를 추정할 수 있는 수식을 함께 제시하였다.

Keywords

Acknowledgement

Grant : 지하공간 환경조성 및 방재기술 개발 - 지하구조물 재해손상 대응기술 개발

References

  1. 건설교통부 (2007), 터널설계기준.
  2. 장수호, 최순욱, 권종욱, 배규진 (2006), "화재에 의한 터널구조물 시공재료의 손상 평가" 대한토목학회논문집, 제26권 제3C호, pp. 219-228.
  3. 장수호, 최순욱, 권종욱, 김상환, 배규진 (2007), "화재 후 터널구조물 시공재료의 역학적 특성변화" 한국터널 공학회논문집, 제9권 제2호, pp. 157-169.
  4. 장수호, 쵠순욱, 배규진, 안성율 (2008), "요소제거기법을 적용한 지하구조물의 화재손상 예측모델 개발", 한국터널공학회 논문집, 제10권 제4호, pp. 1-15.
  5. 최순욱, 장수호, 박태환, 조봉현 (2009), "ISO834(4시간) 화재이력곡선에서의 침매터널 내화재 성능평가", 제35회 대한토목학회 정기학술대회 논문집, pp. 1015-1018.
  6. 日本コンクーリト工學協會 (2002), コンクーリト構造物の火災安全性硏究委員會報告書, pp. 94-112.
  7. ACI (1997), Standard Method for Determining Fire Resistance of Concrete and Mansonry Construction Assemblies, ACI 216.1-97 / TMS 0216.1-97, pp. 1-26.
  8. Ahmed, G.N. (1990), Modelling of coupled heat and mass transfer in concrete structures exposed to elevated temperatures, PhD thesism Kansas State University, Manhattan, Kansas, USA.
  9. ASCE/SFPE29 (1999), Standard calculation method for structural fire protection, Reston, VA, American Society of Civil Engineers.
  10. Bostrom, L. and Larsen, C.K. (2006), "Concrete for tunnel linings exposed to severe fire exposure", Fire Technology, Vol. 42, pp. 351-362. https://doi.org/10.1007/s10694-006-0006-0
  11. Buchanan, A. H. (2002), Structural Design for Fire Safety, WILEY.
  12. Caner, A., Zlatanic, S. and Munfah, N. (2005), "Structural fire performance of concrete and shotcrete tunnel liners", J. Struct. Eng., 131(12), pp. 1920-1925. https://doi.org/10.1061/(ASCE)0733-9445(2005)131:12(1920)
  13. Capua, D.D. and Mari, A.R. (2007), "Nonlinear analysis of reinforced concrete cross-sections exposed to fire", Fire Safety Journal 42, pp. 139-149. https://doi.org/10.1016/j.firesaf.2006.08.009
  14. Carvel, R. (2002), "The history and future of fire tests", Tunnels & Tunnelling International, November 2002, pp. 34-35.
  15. EN1992-1-2 Eurocode 2 (2004), Design of concrete structures, Part 1-2: General rules - Structural Fire Design, Brussels, Commission of European Communities.
  16. Haack, A (1998), "Fire protection in traffic tunnels: general aspects and results of the EUREKA project", Tunneling and Underground Space Technology, Vol. 13, No. 4, pp. 377-381. https://doi.org/10.1016/S0886-7798(98)00080-7
  17. Hertz, K.D. (2003), "Limits of spalling of fire-exposed concrete", Fire Safety Journal, Vol. 38, pp. 103-116. https://doi.org/10.1016/S0379-7112(02)00051-6
  18. Ingason, H and Uonnermark, A (2004), "Recent achivements regarding measuring of time-heat and time-temperature development in tunnels", 1st International Symposium on Safe&Reliable Tunnels, Prague, Czech Republic, 4-6 February.
  19. ITA WG-6 (2004), guidelines for structural fire resistance for road tunnels.
  20. Khoury, G.A. (2000), "Effect of fire on concrete and concrete structures", Prog. Struct. Engng Mater. 2000; 2, pp. 429-447. https://doi.org/10.1002/pse.51
  21. Khoury, G.A., Majorana, C.E., Pesavento, F. and Schrefler, B.A. (2002), "Modelling of heated concrete", Magazine of Concrete Research, 54, No.2, April, pp. 77-101. https://doi.org/10.1680/macr.2002.54.2.77
  22. Khoylou N. (1997), Modelling of moisture migration and spalling behaviour in non-uniformly heated concrete, PhD Thesis, University of London.
  23. Kodur, y.K.R. (2000), "Spalling in high strength concrete exposed to fire-concerns, causes, critical parameters and cures", Proceedings, ASCE Structures Congress, Philadelphia, PA, 2000.
  24. Kodur, V.K.R. and Dwaikat, M. (2008), "A numerical model for predicting the fire resistance of reinforced concrete beams", Cement & Concrete Composites 30, pp. 431-443. https://doi.org/10.1016/j.cemconcomp.2007.08.012
  25. Kodur, V.K.R. and Phan, L. (2007), "Critical factors governing the fire performance of high strength concrete systems", Fire Safety J., Vol. 42, pp. 482-488. https://doi.org/10.1016/j.firesaf.2006.10.006
  26. Kwak, H.Y., Ha, S.J. and Kim, J.K. (2006), "Non-structural cracking in RC walls part I. finite element formulation" Cement and Concrete Research, Vol. 36, pp. 749-760. https://doi.org/10.1016/j.cemconres.2005.12.001
  27. Lamond, J.F. and Pielert, J.H (2006), Significance of tests and properties of concrete & concrete-making materials, ASTM international.
  28. Lamont, S., Usmani, A.S. and Drysdale, D.D. (2001), "Heat transfer analysis of the composite slab in the cardington frame fire tests", Fire Safety Journal 36, pp. 815-839. https://doi.org/10.1016/S0379-7112(01)00041-8
  29. Ono, K. and Otsuka, T. (2006), "Fire design requirement for various tunnel", Proc. of 32nd ITA - World Tunnel Congress, Seoul, Keynote lecture.
  30. Peng, G-F. (2000), "Evaluation of fire damage to high performance concrete" Ph.D. Dissertation, Hong Kong Polytechnic University, pp. 26-48.
  31. Phan, L.T. (1996), Fire performance of high-strength concrete: A report of the state-of-the-Art, NISTIR 5934, National Institute of Standards and Technology, pp. 59-60.
  32. PIARC (1999), "Fire and smoke control in road tunnels", PIARC committee on road tunnels, 5 May 1999.
  33. Pichler, C., Lackner, R. and Mang, H.A. (2006), "Safety assessment of concrete tunnel linings under fire load", J. Struct. Eng., 132(6), pp. 961-969. https://doi.org/10.1061/(ASCE)0733-9445(2006)132:6(961)
  34. Savov, K., Lacker, R. and Mang, H.A. (2005), "Stability assessment of shallow tunnels subjected to fire load", Fire Safety Journal, Vol. 40, pp. 745-763. https://doi.org/10.1016/j.firesaf.2005.07.004
  35. Ulm, F.J., Acker P. and Levy, M. (1999), "The chunnel fire. II: Analysis of concrete damage", Journal of Engineering Mechanics, Vol. 125, No. 3, March, pp. 283-289. https://doi.org/10.1061/(ASCE)0733-9399(1999)125:3(283)