1. 1 指導教授 : 陳瑞昇、董家鈞 老師 學生 : 楊慶中 日期 :99.12.30 1 International Journal of Rock Mechanics & Mining Sciences 39 (2002) 429-442 J. Rutqvist,Y.-S. Wu, C.-F Tsang, G. Bodvarsson

2. 2 Outline  Introduction  FLAC 3D  TOUGH2  Coupling module  Examples Results  Conclusion 2

3. 3 Introduction  Coupled thermal–hydrologic–mechanical processes under multiphase flow conditions are prevalent in geoscientific applications.  A few of the most important include nuclear waste disposal in geological media, deep underground injection of hazardous waste and underground storage of carbon dioxide into permeable aquifers. 3

4. 4 Introduction  However, there is no single computer code that handles general coupled thermal–hydrologic– mechanical processes.  The two codes—TOUGH2 and FLAC 3D are linked using sequential execution and data transfer through nonlinear coupling functions. 4

5. 55 FLAC 3D

6. 6  FALC (Fast Lagrangian Analysis of Continua ), the finite difference code is developed by the United States Itasca Consulting Group Inc in 1986,and FLAC 3D developed in 1994.  Code is developed for rock and soil mechanics and can also handle thermomechanical and hydromechanical problem for single-phase fluid flow. 6

7. 77 Cauchy’s fomula Motion equations FLAC 3D

8. 8

9. 99 TOUGH2

10. 10 TOUGH2  TOUGH(Transport of Unsaturanted Groundwater and Heat) developed in the Earth Sciences Division of Lawrence Berkeley National Laboratory in 1987.  TOUGH2 is a simulator for multiphase, multicomponent, non-isothermal flows in fractured- porous media. 10

11. 11 TOUGH2 Governing equations

12. 12 Coupling module

13. 13

14. 14 Coupling module

15. 15 Coupling module 15

16. 16

17. 17 Examples Results

18. 18 Examples Results 18

19. 19 Examples Results 19

20. 20 Examples Results 20

21. 21 Examples Results 21

22. 22 Examples Results 22

23. 23 Examples Results 23

24. 24 Examples Results 24

25. 25 Examples Results 25

26. 26 Conclusion

27. 27 Conclusion  We have linked two codes—TOUGH2 and FLAC 3D —for analysis of coupled thermal- hydrologic-mechanical processes.  The coupling modules contain nonlinear stress versus permeability functions.

28. Conclusion  In both these examples, the hydromechanical changes are relatively slow, which is most suitable for the sequentially explicit solution.  Problems with higher strain rates relative to fluid mobility may require the sequential implicit approach or ultimately a fully implicit coupled approach.

29. 29 Thank for your attention 29