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Environmental Geology

, 57:1299 | Cite as

Coupled THM processes in EDZ of crystalline rocks using an elasto-plastic cellular automaton

  • Peng-Zhi Pan
  • Xia-Ting Feng
  • Xiao-Hua Huang
  • Qiang Cui
  • Hui Zhou
Special Issue

Abstract

This paper aims at a numerical study of coupled thermal, hydrological and mechanical processes in the excavation disturbed zones (EDZ) around nuclear waste emplacement drifts in fractured crystalline rocks. The study was conducted for two model domains close to an emplacement tunnel; (1) a near-field domain and (2) a smaller wall-block domain. Goodman element and weak element were used to represent the fractures in the rock mass and the rock matrix was represented as elasto-visco-plastic material. Mohr–Coulomb criterion and a non-associated plastic flow rule were adopted to consider the viscoplastic deformation in the EDZ. A relation between volumetric strain and permeability was established. Using a self-developed EPCA2D code, the elastic, elasto-plastic and creep analyses to study the evolution of stress and deformations, as well as failure and permeability evolution in the EDZ were conducted. Results indicate a strong impact of fractures, plastic deformation and time effects on the behavior of EDZ especially the evolution of permeability around the drift.

Keywords

DECOVALEX-THMC EPCA2D EDZ Crystalline rock Fracture network 

Notes

Acknowledgments

This work was supported financially by the National Natural Science Foundation of China (Grant Nos. 40520130315, 50709036). Special thanks are directed to Prof. John A Hudson, Dr. Lanru Jing and Dr. Jonny Rutqvist for their invaluable suggestions and comments. Helpful discussions and contributions were provided by members of DECOVALEX-THMC Task B research teams.

References

  1. Bäckström A (2006) Obtaining the fracture pattern to use in the near field model 2 in phase 3 in Task B in the DECOVALEX IV CooperationGoogle Scholar
  2. Bäckström A, Antikainen J, Backers T, Feng X-T, Jing L, Kobayashi A, Koyama T, Pan P-Z, Rinne M, Shen B, Hudson JA (2008) Numerical modelling of uniaxial compressive failure of granite with and without saline pore water. Int J Rock Mech Min Sci 43:1091–1108Google Scholar
  3. Desai Chandre S, Samtani Naresh C, Vulliet L (1995) Constitutive modeling and analysis of creeping slopes. J Geotech Eng 121(1):43–56CrossRefGoogle Scholar
  4. Ding X-L (2005) Experimental study on rock mass rheological properties and identification for the constitutive model and parameters. Ph.D., Institute of Rock and Soil Mechanics, the Chinese Academy of Sciences, China [in Chinese]Google Scholar
  5. Elsworth D (2003) Some THMC controls on the evolution of fracture permeability. In: Stephansson O, Hudson JA, Jing L (eds) Coupled Thermo-hydro-mechanical-chemical processes in geo-systems, Proc Int Conf GeoProc2003. Stockholm, pp 63–71Google Scholar
  6. Elsworth D, Yasuhara H (2006) Short-mimescale chemo-mechanical effects and their influence on the transport properties of fractured rock. Pure Apply Geophys 163:2051–2070CrossRefGoogle Scholar
  7. Feng XT, Chen SL, Li SJ (2001) Effects of water chemistry on microcracking and compressive strength of granite. Int J Rock Mech and Min Sci 38(4):557–568CrossRefGoogle Scholar
  8. Feng XT, Li SJ, Chen SL (2004) Effect of water chemical corrosion on strength and cracking characteristics of rocks-a review. Key Eng Mater 261–263:1355–1360CrossRefGoogle Scholar
  9. Feng XT, Pan PZ, Zhou H (2006a) Simulation of rock microfracturing process under uniaxial compression using elasto-plastic cellular automata. Int J Rock Mech and Min Sci 43:1091–1108CrossRefGoogle Scholar
  10. Feng X-T, Huang X-H, Pan P-Z (2006b) DECOVALEX THMC Task B, phase 3 stage 3: time dependent failure modelling, extend model for analysis of creep and mechanical degradation, Initial modeling results by the CAS research team[R]. Chinese Academy of Sciences, May 20Google Scholar
  11. Hart RD, John CMST (1986) Formulation of a fully-coupled thermal-mechanical-fluid model for non-linear geologic systems [J]. Int J Rock Mech Min Sic Geomech Abstr 23(3):213–224CrossRefGoogle Scholar
  12. Hudson JA, Christiansson R (2006) Studying coupled effects in the excavation disturbed zone (EDZ) for a crystalline rock: the work of DECOVALEX-THMC Task B. In: Xu W-Y (ed) The 2nd international conference on coupled T-H-M-C processes in geo-systems, Proc Int Conf GeoProc2006. Hohai University, pp 108–117Google Scholar
  13. Hudson JA, Stephansson O, Andersson J (2005) Guidance on numerical modelling of thermo-hydro-mechanical coupled processes for performance assessment of radioactive waste repositories. Int J Rock Mech Min Sci 42(5–6):850–870Google Scholar
  14. Hudson JA, Bäckström A, Rutqvist J, Jing L, Backers T, Chijimatsu M, Feng X-T, Kobayashi A, Koyama T, Lee H–S, Pan P-Z, Rinne M, Shen B (2008) Characterization and modeling the excavation damaged zone (EDZ) in crystalline rock in the context of radioactive waste disposal. Environ Geol (this issue)Google Scholar
  15. Jing L, Feng X-T (2003) Numerical modeling for coupled thermo-hydro-mechanical and chemical processes (THMC) of geological media–international and Chinese experiences[J]. Chin J Rock Mech Eng 22(10):1704–1715Google Scholar
  16. Lewis RW, Schrefler BA (1987) The finite element method in deformation and consolidation of porous media. Wiley, New YorkGoogle Scholar
  17. Liu J, Sheng J, Polak A, Elsworth D, Yasuhara H, Grader A (2006) A fully-coupled hydro- mechanical- chemical model for fracture sealing and preferential opening. Int J Rock Mech Min Sci 43(1):23–36CrossRefGoogle Scholar
  18. Nguyen T-S, Selvadurai APS (1995) Coupled thermal-mechanical-hydrological behaviour of sparsely fractured rock:implications for nuclear, fuel waste disposal. Int J Rock Mech Min Sic Geomech Abstr 32(5):465–479CrossRefGoogle Scholar
  19. Noorishad J, Tsang C-F (1996) ROCMAS-simulator: a thermohydromechanical computer code. In: Stephansson O, Jing L, Tsang C–F (eds) Coupled thermo-hydro-mechanical processes of fractured media. Developments in geotechnical engineering, Elsevier, 79, pp 551–558Google Scholar
  20. Noorishad J, Tsang C-F, Witherspoon PA (1984) Coupled thermal-hydraulic- mechanical phenomena in saturated fractured porous rocks: numerical approach. J Geophysical Res 89(B12):10365–10373CrossRefGoogle Scholar
  21. Ohnishi Y, Shibata H, Kobayashi A (1987) Development of finite element code for the analysis of coupled thermo-hydro-mechanical behavior of a saturated-unsaturated medium. In: Tsang C-F (ed) Proceedings of international symposium on coupled process affecting the performance of a nuclear waste repository, Berkeley, pp 551–557Google Scholar
  22. Pan P-Z, Feng X-T, Hudson JA (2006a) Simulations on Class I and Class II curves by using the linear combination of stress and strain control method and elasto-plastic cellular automata. Int J Rock Mech and Min Sci 43:1109–1117CrossRefGoogle Scholar
  23. Pan P-Z, Feng X-T, Zhou H (2006b) Simulation of rock fracturing in an HM coupling environment using a cellular automaton. In: Xu W-Y (ed) The 2nd international conference on coupled T-H-M-C processes in geo-systems, Proc Int Conf GeoProc2006. Hohai University, pp 503–508Google Scholar
  24. Polak A, Yasuhara H, Elsworth D, Liu J, Grader A, Hallek P (2004) The evolution of permeability in natural fractures—the competing roles of pressure solution and free-face dissolution. In: Stephansson O , Hudson JA, Jing L (eds) Coupled thermo- hydro- mechanical-chemical processes in geo-systems, Proc Int Conf GeoProc2003, Stockholm, p 721–726Google Scholar
  25. Ruqvist J, Stephansson O (2003) The role of hydromechanical coupling in fractured rock engineering. Hydrogeol J 11:7–40CrossRefGoogle Scholar
  26. Rutqvist J (2007) SKI/LBNL’s modeling of Task A2 using ROCMAS code. In: Nguyen TS, Lanru J (eds) DECOVALEX-THMC Project Task A “Influence of near-field coupled THM phenomena on the performance of a spent fuel repository” (Chapter 4), Report of Task A2, DECOVALEX SKI ReportGoogle Scholar
  27. Rutqvist J, Börgesson L, Chijimatsu M, Kobayashi A, Nguyen T-S, Jing L, Noorishad J, Tsang C-F (2001) Thermohydromechanics of partially saturated geological media—governing equations and formulation of four finite element models. Int J Rock Mech Min Sci 38:105–127CrossRefGoogle Scholar
  28. Rutqvist J, Wu Y-S, Tsang C-F, Bodvarsson G (2002) A modeling approach for analysis of coupled multiphase fluid flow, heat transfer, and deformation in fractured porous rock. Int J Rock Mech Min Sci 39:429–442CrossRefGoogle Scholar
  29. Rutqvist J, Sonnenthal E, Jing L, Hudson J (2006a) Task definition for DECOVALEX THMC Task B, Phase 3: a bench mark test on drift wall coupled THMC processesGoogle Scholar
  30. Rutqvist J, Feng X-T, Hudson J, Jing L, Kobayashi A, Koyama T, Pan P-Z, Lee H S, Rinne M, Sonnenthal E, Yamamoto Y (2006b) Multiple-code benchmark simulation study of coupled THMC processes in the excavation disturbed zone associated with geological nuclear waste repositories. In: Xu WY (ed) The 2nd international conference on coupled T-H-M-C processes in geo-systems, Proc Int Conf GeoProc2003. Hohai University, pp 397–402Google Scholar
  31. Rutqvist J, Bäckström A, Chijimatsu M, Feng X-T, Pan P-Z, Hudson JA, Jing L, Kobayashi A, Koyama T, Lee HS, Huang X-H, Rinne M, Shen B (2008a) A bench mark simulation study of the long-term EDZ evolution of geological nuclear waste repositories. Environ Geol (this issue)Google Scholar
  32. Rutqvist J, Barr D, Birkholzer JT, Fujisaki K, Kolditz O, Liu Q-S, Fujita T, Wang W, Zhang C-Y (2008b) A comparative simulation study of coupled THM processes and their effect on fractured rock permeability around nuclear waste repositories. Environ Geol (this issue)Google Scholar
  33. Rutqvist J, Börgesson L, Chijimatsu M, Hernelind J, Jing L, Kobayashi A, Nguyen T-S (2008c) Modeling of damage, permeability changes and pressure responses during excvation of the TSX tunnel in granitic rock at URL, Canada. Environ Geol (this issue)Google Scholar
  34. Shen B, Stephansson O (1993) Numerical analysis of mixed mode-I and mode-II fracture propagation. Int J Rock Mech Min Sci 30:861–867CrossRefGoogle Scholar
  35. Stephansson O, Jing L, Hudson JA (eds) (1996) Coupled T-H-M-C processes of fractured media. Devel Geotech Eng 79, Elsevier, AmsterdamGoogle Scholar
  36. Stephansson O, Jing L, Hudson JA (eds) (2004) Coupled T-H-M-C processes in geosystems: fundamentals, modeling, experiment and applications, Elsevier, OxfordGoogle Scholar
  37. Tsang C-F (ed) (1987) Coupled processes associated with nuclear waste repositories. Academic Press, New YorkGoogle Scholar
  38. Tsang C-F, Stephansson O, Jing L, Kautsky F (2008) An overview of the DECOVALEX project 1992–2007. Environ Geol (this issue)Google Scholar
  39. Yasuhara H, Elsworth D (2006a) A numerical model simulating reactive transport and evolution of fracture permeability. Int J Numer Anal Meth Geomech 30:1039–1062CrossRefGoogle Scholar
  40. Yasuhara H, Elsworth D (2006b) A numerical model simulating evolution of fracture permeability moderated by mechanically- and chemically-induced dissolution. In: Xu W-Y (ed) The 2nd international conference on coupled T-H-M-C processes in geo-systems, Proc Int Conf GeoProc2003. Hohai University, pp 338–343Google Scholar

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Peng-Zhi Pan
    • 1
  • Xia-Ting Feng
    • 1
  • Xiao-Hua Huang
    • 1
  • Qiang Cui
    • 2
  • Hui Zhou
    • 1
  1. 1.State Key Laboratory of Geomechanics and Geotechnical EngineeringInstitute of Rock and Soil Mechanics, Chinese Academy of SciencesWuhanChina
  2. 2.Northeastern UniversityShenyangChina

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