Advertisement

Evaluation on the Minimum Principal Stress State and Potential Hydraulic Jacking from the Shotcrete-Lined Pressure Tunnel: A Case from Nepal

  • Chhatra Bahadur BasnetEmail author
  • Krishna Kanta Panthi
Original Paper
  • 57 Downloads

Abstract

Reliable estimation of in situ stress state is very important in implementing unlined/shotcrete-lined pressure tunnels and shafts. The topography, local tectonic setting and geological environment greatly influence the magnitude of in situ stress level. This paper aims to evaluate in situ stress state at the Upper Tamakoshi Hydroelectric Project (UTHP), where unlined/shotcrete-lined headrace tunnel with considerable hydrostatic head is being implemented. Initially measured minimum principal stress indicated much lower values than the hydrostatic pressure at the downstream end of the headrace tunnel, which led to shift the alignment at the upper elevation with reduced hydrostatic pressure. In order to explore the reason behind much lower stress level as expected, a comprehensive assessment is carried out by developing a full rock stress model so that the minimum principal stress along the unlined pressure tunnel is evaluated. To address the complex geotectonic and topographic environment of the UTHP project area, a final rock stress model (FRSM) concept as suggested by Stephansson and Zang (2012) has been utilized. The FRSM concept considers stepwise evaluation of the in situ stress state analysis integrating the best estimate stress model (BESM), stress measurement methods (SMM) and integrated stress determination methods (ISD). The analysis carried out revealed that the in situ stress state at the project area has high degree of spatial variation even at the similar overburden due to the presence of complex topography and the presence of local shear and weakness zones. The analysis further demonstrates that a presence of local shear/weakness zone has considerable de-stressing effect, which leads to the reduction of in situ minimum principal stress magnitude. The reduction in the minimum principal stress along the pressure tunnel increases the risk for the potential hydraulic jacking and leakage if static water pressure is higher than the magnitude of minimum principal stress.

Keywords

Himalayan geology and tectonics Topography Weakness zones Unlined/shotcrete-lined pressure tunnel In situ stress state 3D numerical modeling 

Notes

Acknowledgements

The authors are grateful to the project management team of Upper Tamakoshi Hydroelectric Project for providing project data and information and giving permission to carry out research on this project, which will be a milestone in the use of unlined pressure tunnel concept in the Himalayan region.

References

  1. Amadei B, Pan E (1995) Role of topography and anisotropy when selecting unlined pressure-tunnel alignment. J Geotech Eng 121(12):879–885CrossRefGoogle Scholar
  2. Ask D (2006) New developments in the Integrated Stress Determination Method and their application to rock stress data at the Äspö HRL, Sweden. Int J Rock Mech Min Sci 43(1):107–126CrossRefGoogle Scholar
  3. Barton N (1973) A review of the shear strength of filled discontinuities in rock. In: Fjellspregningsteknikk, Bergmekanikk. Tapir Press, Oslo Trondheim, pp. 19.1–19.38Google Scholar
  4. Barton N (1995) The influence of joint properties in modelling jointed rock masses. 8th ISRM congressGoogle Scholar
  5. Benson R (1989) Design of unlined and lined pressure tunnels. Tunnel Undergr Space Technol 4(2):155–170CrossRefGoogle Scholar
  6. Bergh-Christensen J (1982) “Design of Unlined Pressure Shaft at Mauranger Power Plant Norway.” ISRM International Symposium. International Society for Rock MechanicsGoogle Scholar
  7. Brekke TL, Ripley BD (1987) Design guidelines for pressure tunnels and shafts (No. EPRI-AP-5273). California Univ. at Berkeley, Dept. of Civil Engineering; Electric Power Research Inst., Palo Alto, CA (USA)Google Scholar
  8. Broch E (1982) The development of unlined pressure shafts and tunnels in Norway. ISRM International Symposium. International Society for Rock MechanicsGoogle Scholar
  9. Buen B (1984) Documentation unlined water conduits in Norway. Hard Rock Engineering, FHS, Oslo, NorwayGoogle Scholar
  10. Broch E (1984) Unlined high pressure tunnels in areas of complex topography. Int Water Power Dam Constr 36(11)Google Scholar
  11. Buen B, Palmstrom A (1982) Design and Supervision of Unlined Hydro Power Shafts and Tunnels with Head up to 590 Meters. ISRM International Symposium. International Society for Rock MechanicsGoogle Scholar
  12. Cornet FH, Valette B (1984) In situ stress determination from hydraulic injection test data. J Geophys Res: Solid Earth 89(B13):11527–11537CrossRefGoogle Scholar
  13. Cornet FH (1993) The HTPF and the integrated stress determination methods. Compres Rock Eng 3:413–432Google Scholar
  14. Doe TW, Korbin GE (1987) A comparison of hydraulic fracturing and hydraulic jacking stress measurements. 28th US Symposium on Rock Mechanics (USRMS). American Rock Mechanics AssociationGoogle Scholar
  15. Figueiredo B, Cornet FH, Lamas L, Muralha J (2014) Determination of the stress field in a mountainous granite rock mass. Int J Rock Mech Min Sci 72:37–48CrossRefGoogle Scholar
  16. Gercek H (2007) Poisson’s ratio values for rocks. Int J Rock Mech Min Sci 44(1):1–13CrossRefGoogle Scholar
  17. Goguel J (1946) Introduction à l’étude mécanique des déformations mécaniques de l’écorce terrestre. Mémoire pour servir à l’introduction de la carte géologique de France (in French). ParisGoogle Scholar
  18. Haimson BC, Cornet FH (2003) ISRM suggested methods for rock stress estimation—part 3: hydraulic fracturing (HF) and/or hydraulic testing of pre-existing fractures (HTPF). Int J Rock Mech Min Sci 40(7–8):1011–1020CrossRefGoogle Scholar
  19. Hart R (2003) Enhancing rock stress understanding through numerical analysis. Int J Rock Mech Min Sci 40(7–8):1089–1097CrossRefGoogle Scholar
  20. Hartmaier HH, Doe TW, Dixon G (1998) Evaluation of hydro jacking tests for an unlined pressure tunnel. Tunnel Undergr Space Technol 13(4):393–401CrossRefGoogle Scholar
  21. Hoek E, Diederichs M (2006) Empirical estimation of rock mass modulus. Int J Rock Mech Min Sci 43(2):203–215CrossRefGoogle Scholar
  22. Holter KG, Nilsen B, Langås C, Tandberg MK (2014) Testing of sprayed waterproofing membranes for single-shell sprayed concrete tunnel linings in hard rock. In: Proceedings of the world tunnel congressGoogle Scholar
  23. Hudson JA, Harrison JP (2000) Engineering rock mechanics: an introduction to the principles. ElsevierGoogle Scholar
  24. Hudson JA, Cornet FH, Christiansson R (2003) ISRM suggested methods for rock stress estimation-Part 1: strategy for rock stress estimation. Int J Rock Mech Min Sci 40(7–8):991–998CrossRefGoogle Scholar
  25. ITASCA (2017) FLAC3D 5.0 User’s MannualGoogle Scholar
  26. Jackson J, McKenzie D, Priestley K, Emmerson B (2008) New views on the structure and rheology of the lithosphere. J Geol Soc 165(2):453–465CrossRefGoogle Scholar
  27. Larson KP (2012) The geology of the Tama Kosi and Rolwaling Valley region, east-central Nepal. Geosphere 8(2):507–517CrossRefGoogle Scholar
  28. Lavé J, Avouac J-P (2000) Active folding of fluvial terraces across the Siwaliks Hills, Himalayas of central Nepal. J Geophys Res: Solid Earth (1978–2012) 105(B3):5735–5770CrossRefGoogle Scholar
  29. Li G, Mizuta Y, Ishida T, Li H, Nakama S, Sato T (2009) Stress field determination from local stress measurements by numerical modelling. Int J Rock Mech Min Sci 46(1):138–147CrossRefGoogle Scholar
  30. Ljunggren C, Chang Y, Janson T, Christiansson R (2003) An overview of rock stress measurement methods. Int J Rock Mech Min Sci 40(7–8):975–989CrossRefGoogle Scholar
  31. Lu M (2006) Interpretation of in-situ rock stress measurement by overcoring. In: Proceedings of the international symposium on in-situ rock stress, Trondheim, Norway, pp. 393–397Google Scholar
  32. Nakata T (1989) Active faults of the Himalaya of India and Nepal.” Special Paper of the Geological Society of America, pp 243–264Google Scholar
  33. Nakata T, Otsuki K, Khan SH (1990) Active faults, stress field and plate motion along the Indo-Eurasian plate boundary. Tectonophysics 181(1–4):8391–8895Google Scholar
  34. Nilsen B, Thidemann A (1993) Rock engineering. Norwegian Institute of Technology, Division of Hydraulic EngineeringGoogle Scholar
  35. Norconsult (2005) Feasibility study report of Upper Tamakoshi Hydroelectric Project, Nepal. Nepal Electricity AuthorityGoogle Scholar
  36. Norconsult, Lahmeyer (2008) Detailed design report of Upper Tamakoshi Hydroelectric Project, Nepal. Nepal Electricity Authority Google Scholar
  37. Palmstrom A (1995) RMi—a rock mass characterization system for rock engineering purposes.” PhD thesis. Department of geology, University of Oslo, 400 p. or on http://www.rockmass.net
  38. Panthi KK (2006) Analysis of engineering geological uncertainties related to tunnelling in Himalayan rock mass conditions. PhD Thesis, NTNU, Trondheim, NorwayGoogle Scholar
  39. Panthi K (2012) Evaluation of rock bursting phenomena in a tunnel in the Himalayas. Bull Eng Geol Env 71(4):761–769CrossRefGoogle Scholar
  40. Panthi KK (2014) Norwegian design principle for high pressure tunnels and shafts: it’s applicability in the Himalaya. Hydro Nepal: J Water Energy Environ 14:36–40CrossRefGoogle Scholar
  41. Panthi KK, Basnet CB (2017) Design review of the headrace system for the Upper Tamakoshi project, Nepal. Int J Hydropower Dams 24(1):60–67Google Scholar
  42. Parker RL, McNutt MK (1980) Statistics for the one-norm misfit measure. J Geophys Res: Solid Earth 85(B8):4429–4430CrossRefGoogle Scholar
  43. Revets SA (2009) One-norm misfit statistics. Geophys Res Lett 36(20)Google Scholar
  44. Rowley DB (1996) Age of initiation of collision between India and Asia: a review of stratigraphic data. Earth Planet Sci Lett 145(1):1–13CrossRefGoogle Scholar
  45. Selmer-Olsen R (1969) Experience with unlined pressure shafts in Norway. In: Proc. Int. Symposium On Large Permanent Underground Openings, OsloGoogle Scholar
  46. Selmer-Olsen R (1974) Underground openings filled with high-pressure water or air. Bull Int Assoc Eng Geol 9(1):91–95CrossRefGoogle Scholar
  47. SINTEF (2008) Rock stress measurement at the Upper Tamakoshi Hydroelectric project. SBF IN F08112Google Scholar
  48. SINTEF (2013) Rock stress measurement by hydraulic fracturing at the Upper Tamakoshi Hydroelectric project, Nepal. SBF IN F08112Google Scholar
  49. Stephansson O, Zang A (2012) ISRM suggested methods for rock stress estimation—part 5: establishing a model for the in situ stress at a given site.” ISRM Suggested Methods for Rock Characterization, Testing and Monitoring: 2007–2014, pp 187–201Google Scholar
  50. Tarantola A (2005) Inverse problem theory and methods for model parameter estimation (Vol. 89)Google Scholar
  51. Upreti B (1999) An overview of the stratigraphy and tectonics of the Nepal Himalaya. J Asian Earth Sci 17(5):577–606CrossRefGoogle Scholar
  52. Yin JM, Cornet FH (1994) Integrated stress determination by joint inversion of hydraulic tests and focal mechanisms. Geophys Res Lett 21(24):2645–2648CrossRefGoogle Scholar
  53. Zang A, Stephansson O (2010) Stress field of the Earth’s crust. Springer Science & Business MediaGoogle Scholar

Copyright information

© Springer-Verlag GmbH Austria, part of Springer Nature 2019

Authors and Affiliations

  • Chhatra Bahadur Basnet
    • 1
    Email author
  • Krishna Kanta Panthi
    • 1
  1. 1.Department of Geoscience and PetroleumNorwegian University of Science and TechnologyTrondheimNorway

Personalised recommendations