Investigation of a methane flare during the excavation of the Silvan irrigation tunnel, Turkey

  • Mustafa Ayhan
  • Deniz Aydın
  • M. Şefik İmamoğlu
  • Mustafa Çoğalan
  • Askeri Karakuş
Original Paper


Mechanized methods are being increasingly used in tunnel excavations to such an extent that to ensure safe construction and the economic viability of projects the need for design-stage geotechnical studies has considerably increased. However, unexpected problems, such as gas inflow, can be experienced during excavation when the geological conditions are insufficiently investigated. In fact, even if construction is taking place in a known oil–natural gas basin or coal-bearing strata, the possibility of methane flare/explosion events can be minimized if a suitable excavation method and equipment are used. However, little published literature is available on this topic, resulting in the potential problem of encounters with sources of methane during construction that have not been considered in the planning of the tunneling operations. We have studied a methane (natural gas) flare incident that occurred in 2015 during the excavation by full-face hard rock tunnel boring machine of the Silvan irrigation tunnel, south-eastern Turkey. During the planning and pre-construction stages no consideration was given to the fact that the tunnel passes through a natural gas basin and, consequently, the selection of excavation method and machine equipment was made without taking into account the high possibility of natural gas being present. During excavation a significant methane gas flare occurred, resulting in 13 workers being injured and abandonment of the project. Subsequent investigations revealed that the proposed route of the tunnel passed through a natural gas basin and that Turkish Petroleum Corporation (TPAO) had carried out natural gas exploration in the area. Here we provide details on the geological background and the flare incident itself and come to the conclusion that the pre-construction ground investigations for this project were grossly inadequate. We also suggest that in order to facilitate economical and safe tunnel construction, consideration should always be given to the possible presence of methane and other gases at the ground investigation stages of tunneling projects and that all previous geological and technical studies related to the study area should be taken into consideration during the pre-construction stage.


TBM tunneling Gassy ground Methane flare Methane explosion Geotechnical investigations 


  1. Ateş U, Bilgin N, Çopur H (2014) Estimating torque, thrust and other design parameters of different type TBMs with some criticism to TBMs used in Turkish tunneling projects. Tunn Undergr Space Technol 40:46–63CrossRefGoogle Scholar
  2. Bandini A, Beery P, Cormio C, Colaiori M, Lisardi A (2017) Safe excavation of large section tunnels with earth pressure balance tunnel boring machine in gassy rock masses: the Sparvo tunnel case study. Tunn Undergr Space Technol 67:85–97CrossRefGoogle Scholar
  3. BAR-SU Engineering & Consultancy Inc. (2011) Engineering geology report. The 10th Regional Directorate 06/04/2011. General Directorate of State Hydraulic Works, Ankara, pp 1–124Google Scholar
  4. Belle B, Faulstone A (2015) Explosion prevention in a coal mine TBM drifts—an operational knowledge share. In: 15th Coal Operators’ Conference. The Australian Institute of Mining and Metallury and Mine Managers Association of Australia, University of Wollongong, pp 271–282Google Scholar
  5. Çopur H, Çınar M, Ökten G, Bilgin N (2012) A case study on the methane explosion in the excavation chamber of an EPB-TBM and lessons learnt including some recent accidents. Tunn Underground Space Technol 27:159–167Google Scholar
  6. Grandori R (2006) Abdalajis East Railway Tunnel (Spain) double shield universal TBM cope with extremely poor and squeezing formations. Tunn Underground Space Technol 21:268Google Scholar
  7. Herrenknecht AG (2018) Available at: Accessed 19 Jan 2018
  8. İlci N, Temel M, Sezgin S, Polat C, Bilgin N (2014) Effect of cutter clogging on performance of tunnel boring machine (TBM). Turkish Tunneling and Underground Technologies Magazine 6:84–86. ISSN 2148–1768Google Scholar
  9. Kitajima M (2017a) Methane gas explosion hazard during construction of headrace tunnel for agriculture. Available at: Accessed 09 Feb 2017
  10. Kitajima M (2017b) Methane gas explosion hazard of an earth pressure type shield tunnel. Available at: Accessed 09 Feb 2017
  11. Kissel FN (2006) Preventing methane gas explosions during tunnel construction. In: Kissel FN (ed) Handbook for methane control in mining. Information Circular 9486. National Institute for Occupational Safety and Health (NIOSH), Pittsburgh, pp 169–184Google Scholar
  12. Lockyer JW, Howcroft A (1997) The Abbeystead explosion disaster. Ann Burns Fire Disasters 10, September 1–4Google Scholar
  13. Paltrinieri E, Sandrone F, Zhao J (2016) Analysis and estimation of gripper TBM performances in highly fractured and faulted rocks. Tunn Undergr Space Technol 52:44–61CrossRefGoogle Scholar
  14. Pearson CFC, Edwards JS, Durucan S (1989) Methane occurrences in the Carsington Aqueduct tunnel project—a case study. In: Proc of the Rapid Excavation and Tunneling Conference, Los Angeles, 11–14 June, pp 176–195Google Scholar
  15. Peters JF, Breu FA, Neyer RF, Gorman RF, Critchfield JW (1985) Sewer tunnel in gassy rock. In: Proc of the Rapid Excavation and Tunneling Conference, June 16-20, Society of Mining Engineers, New York, pp 462–481Google Scholar
  16. Price DG (2009) Engineering geology, principles and practice. Springer, Berlin, XVIII, p 450Google Scholar
  17. Proctor RJ (2002) The San Fernando tunnel explosion. Eng Geol 67:1–3CrossRefGoogle Scholar
  18. Rodriguez R, Lombardia C (2010) Analysis of methane emissions in a tunnel excavated through carboniferous strata based on underground coal mining experience. Tunn Undergr Space Technol 25:456–468CrossRefGoogle Scholar
  19. Schafer M, Pintabona R, Lukajik B, Kritzer M, Janoska S, Switalski R (2007) Gas mitigation in the Mill Creek Tunnel. In: Proc of the Rapid Excavation and Tunneling Conference, pp 168–175Google Scholar
  20. Shahriar K, Rostami J, Hamidi JK (2009) TBM tunneling and analysis of high gas emission accident in Zagros long tunnel. In: Proc of the World Tunnelling Congress, Budapest-Hungary, pp 171–172Google Scholar
  21. Turkish Petroleum Corporation (TPAO) (2015) Dated annotation 20.05.2015. TPAO Department of Research, AnkaraGoogle Scholar
  22. U.S. National Committee on Tunnelling Technology (1984) Geotechnical site investigations for underground projects. National Academy of Engineering, Washington D.C.Google Scholar
  23. Wightman NR, Mackay A (2008) Gas ground investigation for tunneling works at Hung Hom freight depot, Hong Hong. In: Proc of the World Tunnel Congress, Agra, India, pp 98–109Google Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  • Mustafa Ayhan
    • 1
  • Deniz Aydın
    • 1
  • M. Şefik İmamoğlu
    • 1
  • Mustafa Çoğalan
    • 2
  • Askeri Karakuş
    • 1
  1. 1.Department of Mining EngineeringDicle UniversityDiyarbakırTurkey
  2. 2.Yertaş ConstructionAnkaraTurkey

Personalised recommendations