Acta Mechanica Solida Sinica

, Volume 25, Issue 6, pp 651–662 | Cite as

FEM Analysis for Influences of a Fault on Coupled T-H-M-M Process in Dual-Porosity Rock Mass

Article

Abstract

For the case in which a large geological structure like fault existing within the surrounding rock mass in the near field of a repository for high-level radioactive nuclear waste, one kind of coupled thermo-hydro-mechanical-migratory model of dual-porosity medium for saturated-unsaturated ubiquitous-joint rock mass was established. In the present model, the seepage field and the concentration field are double, but the stress field and the temperature field are single, and the influences of sets, spaces, angles, continuity ratios, stiffness of fractures on the constitutive relationship of the medium can be considered. At the same time, a two-dimensional program of finite element method was developed. Taking a hypothetical nuclear waste repository located at a rock mass being unsaturated dual-porosity medium as a calculation example, the FEM analysis for thermo-hydro-mechanical-migratory coupling were carried out under the condition of radioactive nuclide leaking for the cases with and without a fault, and the temperatures, pore pressures, flow velocities, nuclide concentrations and principal stresses in the rock mass were investigated. The results show that the fracture water in the fault flows is basically along the fault direction, and its flow velocity is almost three orders of magnitude higher than that of fracture water in rock mass; the nuclide concentration in the fault is also much higher than that without fault, and the nuclides move along the fault faster; moreover, the fault has obvious influences on the pore pressures and the principal stresses in the rock mass.

Key words

fault dual-porosity medium thermo-hydro-mechanical-migratory coupling FEM analysis 

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References

  1. [1]
    Wang, J., Zheng, H.L., Xu, G.Q., Fan, X.H., Wang, C.Z. and Fan, Z.W., Geological disposal of high level radioactive waste in China: progress in last decade (1991–2000). In: Wang Ju, Fan Xianhua, Xu Guoaing, Zheng Hualing, editors, Geological Disposal of High Level Radioactive Waste in China: Progress in Last Decade. Beijing: Atomic Energy Press, 2004: 1–12 (in Chinese).Google Scholar
  2. [2]
    TRW Environmental Safety Systems Inc., Drift Scale Test Progress Report No.1. Las Vegas: TRW Environmental Safety Systems Inc., 1998.Google Scholar
  3. [3]
    Min, M.Z. and Xu, G.Q., Principles for Disposal of Radioactive Waste. Beijing: Atomic Energy Press, 1998 (in Chinese).Google Scholar
  4. [4]
    Ohnishi, Y., Chan, T. and Jing, L., Constitutive models for rock joins. In: Stephansson, O., Jing, L., Tsang, C.-F., eds. Coupled Thermo-Hydro-Mechanical Processes of Fractured Media, Vol. 79. Elsevier: Development in Geotechnical Engineering, 1996: 57–91.CrossRefGoogle Scholar
  5. [5]
    Rutqvist, J., Chijimatsu, M., Jing, L., Millard, A., Nguyen, T.S., Rejeb, A., Sugita, Y. and Tsang, C.F., Anumerical study of THM effects on the near-field safety of a hypothetical nuclear waste repository—BMT1 of the DECOVALEX III project. Part 3: Effects of THM coupling in sparsely fractured rocks. International Journal of Rock Mechanics and Mining Sciences, 2005, 42(5–6): 745–755.CrossRefGoogle Scholar
  6. [6]
    Jing, L.R. and Feng, X.T., Main rock mechanics issures in geological disposal of radioactive wastes. Chinese Journal of Rock Mechanics and Engineering, 2006, 25(4): 833–841 (in Chinese).MathSciNetGoogle Scholar
  7. [7]
    Noorishad, J. and Tsang, C.F., Coupled thermohydroelasticity phenomena in variably saturated fractured porous rocks—Formulation and numerical solution. In: Stephansson, O., Jing, L. and Tsang, C.-F. editor, Coupled Thermo-Hydro-Mechanical Progresses of Fractured Media, 79, Elsevier: Development in Geotechnical Engineering, 1996, 93–134.CrossRefGoogle Scholar
  8. [8]
    Nguyen, T.S., Description of the computer code FRACON. In: Stephansson, O., Jing, L. and Tsang, C.-F. editor, Coupled Thermo-Hydro-Mechanical Progresses of Fractured Media, 79, Elsevier: Development in Geotechnical Engineering, 1996: 539–544.CrossRefGoogle Scholar
  9. [9]
    Tijani, S.-M. and Vouille, G., FEM analysis of coupled THM processes in fractured media with explicit representation of joints. In: Stephansson, O., Jing, L. and Tsang, C.-F. editor, Coupled Thermo-Hydro-Mechanical Progresses of Fractured Media, 79, Elsevier: Development in Geotechnical Engineering, 1996: 165–180.CrossRefGoogle Scholar
  10. [10]
    Zhang, Y.J., A kind of joint element simulating coupled thermo-hydro-mechanical phenomenon and relevant numerical analyses. Chinese Journal of Geotechnical Engineering, 2005, 27(3): 270–274 (in Chinese).MathSciNetGoogle Scholar
  11. [11]
    Zhang, Y.J., 3D joint element and relevant numerical analysis simulating coupled thermo-hydro-mechanical processes. Chinese Journal of Geotechnical Engineering, 2009, 31(8): 1213–1218 (in Chinese).Google Scholar
  12. [12]
    Liang, B., Liu, L., Xue, Q. and Sun, W.J., Study on numerical simulation of nuclides leakage for groundwater pollution. Journal of System Simulation, 2007, 19(2): 261–311 (in Chinese).Google Scholar
  13. [13]
    Olivella, S. and Gens, A., Double structure THM analyses of a heating test in a fractured tuff incorporating intrinsic permeability variations. International Journal of Rock Mechanics and Mining Sciences, 2005, 42(5/6): 667–679.CrossRefGoogle Scholar
  14. [14]
    Rutqvis, J. and Tsang, C.-F., Analysis of thermal-hydrologic-mechanical behavior near an emplacement drift at Yucca mountain. Journal of Contaminant Hydrology, 2003, 62–63: 637–652.CrossRefGoogle Scholar
  15. [15]
    Nishigaki, M., Density Dependent Transport Analysis Saturateds-Unsaturated Porous Media—3 Dimensional Eulerian Lagrangian Method. Okayama University, 2001.Google Scholar
  16. [16]
    Elsworth, D. and Mao, B., Flow-deformation response of dual-porosity media. Journal of Geotechnical Engineering, 1992, 118(1): 107–124.CrossRefGoogle Scholar
  17. [17]
    Rutqvist, J., Barr, D., Datta, R., Gens, A., Millard, A., Olivella, S., Tsang, C.-F. and Tsang, Y., Coupled thermal-hydrological-mechanical analyses of the Yucca Mountain Drift Scale Test—Comparison of field measurements to predictions of four different numerical models. International Journal of Rock Mechanics and Mining Sciences, 2005, 42(5/6): 680–697.CrossRefGoogle Scholar

Copyright information

© The Chinese Society of Theoretical and Applied Mechanics and Technology 2012

Authors and Affiliations

  1. 1.State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil MechanicsThe Chinese Academy of SciencesWuhanChina
  2. 2.Technology CentreChina Railway Tunnel Group Co. LtdLuoyangChina

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