Thermo-hydro-mechanical coupling

All these processes are the product of a system driven by the Earth s climate and characterised by strong thermo-hydro-mechanical coupling, in which both chemical processes and transient phenomena are important. 

Stephansson et al., O. 1995. Thermo -Hydro -Mechanical Coupling in Rock Mechanics. 

Abstract motif is a three-dimensional finite-element code developed to simulate groundwater flow, heat transfer and solute transport in deformable fractured porous media. The code has been subjected to an extensive verification and updating programme since the onset of its development. In this paper, additional verification and validation works with an emphasis on thermo-hydro-mechanical processes are presented. The verification results are based on cases designed to verify thermo-hydro-mechanical coupling terms, and isothermal and non-isothermal consolidations. A number of validation case studies have been conducted on the code. Example results are repotted in this paper. 

ON THE CONSTITUTIVE MODELLING OF THERMO-HYDRO-MECHANICAL COUPLING IN ELASTIC MEDIA WITH DOUBLE POROSITY... 

Collin, F. Li, X.L. Radu, J.P. Charlier, R. 2002a. Thermo-hydro-mechanical couplings in clay barriers. Engineering Geology (64) pp. 179-193. 

The coupling effects of various poromechanical processes on the response of a porous medium have been successfully addressed by Biot s theory of poroelasticity and its extensions [3,4,5,8,2], The chemical effects have also been addressed by considering interaction between the porous matrix and a pore fluid comprising of a solute and solvent [10, 7, 6], Comprehensive anisotropic poromechanics formulations and corresponding solutions for the inclined borehole problem have been presented [4—2], However, the coupled chemo-thermo-hydro-mechanical response of an anisotropic porous medium has not been addressed to date. 

In this paper, the focus is on the development of a poromechanics model which addresses the chemical effects within the framework of the anisotropic porothermoelastic model [2], The resulting model, termed as porochemo-thermoelastic, accounts for fully coupled chemo-thermo-hydro-mechanical response of a chemically active formation saturated with a pore fluid comprising of two species under non-isothermal conditions. The numerical example presented demonstrates the thermo-chemical effect on the stress and pore pres-... 

To understand and predict the effects of coupled processes in all these practical problems, models are being developed that are capable of simulating coupled thermo-hydro-mechanical (THM) processes. The term coupled processes implies that one process affects the initiation and progress of another. Thus, the rock mass behavior cannot be predicted with confidence by considering each process individually or in simple succession. Previously, binary TM and TH couplings have been studied in the context of, for example, rock... 

Stephansson, O., L. Jing and C.-F. Tsang. 1996. Coupled Thermo-Hydro-Mechanical Processes of Fractured Media—Mathematical... 

Models and methods for coupled thermo-hydro-mechanical processes of fractured rocks, in saturated conditions using crack-tensor approach (Liu et al., 2002), the equivalent continuum approach and FEM solution technique with consideration for two-phase flow of water/vapour due to phase change by evaporation for fully or partially saturated cases (Li et al., 2000). 

Chen B, Li N and Zhuo R. 2001. FEM analysis on fully coupled thermo-hydro-mechanical behaviour of porous media. Chinese J. of Rock Mech. Engng., 20(4), pp. 467-472. 

Fujita T., Kobayashi A. and Borgesson L. 1996. Experimental investigation and mathematical simulation on coupled T-H-M processes of the engineered buffer materials, the TC3 problem. In Stephansson O, Jing L, Tsang C-F editors. Coupled thermo-hydro-mechanical processes of fractured media. Developments in Geotechnical Engineering, No.79, Amsterdam Elsevier, pp.369-392. 

Ohnishi, Y., Shibata, H. and 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. editor. Coupled processes associated with nuclear waste repositories. Academic lYess, Orlando, pp.551-557. 

Tijani, S.M. 1996. Short description of VIPLEF code. Coupled thermo-hydro-mechanical processes of fractured media. Developments in Geotechnical Engineering, 79 507 - 511. 

NUMERICAL SIMULATION OF VARIABLY COUPLED THERMO-HYDRO-MECHANICAL PROCESSES IN FRACTURED POROUS MEDIA... 

Model performance is demonstrated for a simplified three-dimensional test case that takes into consideration both the thermo-hydro-mechanical interaction and a stress dependent permeability. The functionality of the described control concept for the coupled processes is illustrated by some selected simulations of Benchmark Test IB (BMTIB) of DECOVALEX III. 

Nguyen TS, Chijimatsu M, De Jonge J, Jing L, Kohlmeier M, Millard A, Rejeb A, Rutqvist J, Souley M and Sugita Y. 2003. Implications of coupled Thermo-Hydro-Mechanical processes on the safety of a hypothetical nuclear fuel waste repository. GeoProc, Stockholm, Sweden... 

Ohnishi, Y. and Kobayashi, A. 1996. THAMES. In Stephansson, O., Jing, L., and Tsang, C.-F. editors. Coupled Thermo-hydro-mechanical Processes of Fractured Media. Developments in Geotechnical Engineering, Elsevier, 79 pp. 545-549. 

IMPLICATIONS OF COUPLED THERMO-HYDRO-MECHANICAL PROCESSES ON THE SAFETY OF A HYPOTHETICAL NUCLEAR FUEL WASTE REPOSITORY... 

Chan, T. Guvanasen, V. and Stanchell, F.W. 2003. Verification and validation of a three-dimensional finite-element code for coupled Thermo-Hydro-Mechanical and Salinity (T-H-M-C) modelling in fractured rock mass. This conference. 

THERMO-HYDRO-MECHANICAL IMPACTS OF COUPLING BETWEEN GLACIERS... 

A RESEARCH PROGRAM FOR NUMERICAL EXPERIMENTS ON THE COUPLED THERMO-HYDRO-MECHANICAL AND CHEMICAL PROCESSES IN THE NEAR-FIELD OF A HIGH-LEVEL RADIOACTIVE WASTE REPOSITORY... 

Abstract In the near-field of a high-level radioactive waste (HLW) repository, the coupled thermo -hydro -mechanical and chemical (T-H-M-C) processes will occur. Observation periods by laboratory and in-situ experiments are very short and information by natural analogue studies is very limited, so numerical experiments are the only available approach to predict the near-field long-term evolution. We have initiated a research on the coupled T-H-M-C processes and are trying to carry out numerical experiments on the coupled T-H-M-C processes in order to predict the near-field long-term evolution. This paper presents our current status and future activities on the research for numerical experiments on the coupled T-H-M-C processes. 

In the near-field of a HLW repository, the coupled thermo -hydro -mechanical and chemical (T-H-M-C) processes will occur, involving the interactive processes among radioactive decay heat from the vitrified waste, infiltration of groundwater into bentonite, swelling pressure of bentonite due... 

Our activities on development of the coupled T-H-M-C code and further demonstration analysis are presented by Neyama et al. in GeoProc 2003 conference, entitled Prototype Code Development for Numerical Experiments on the Coupled Thermo-Hydro-Mechanical and Chemical Processes in the Near-field of a High-level Radioactive Waste Repository . The prototype code is based on the coupled T-H-M code, mass transport code and geochemical code which have been well verified and validated through benchmark tests and various experiments, and... 

Chijimatsu, M., Fujita, T., Kobayashi, A. Ohnishi, Y. 1999. Coupled Thermo-Hydro-Mechanical Experiment at Kamaishi Mine, Technical Note 16-99-03, Analyses of Task 2C, DECOVALEXII. JNC TN8400 99-031. 

Numerical Approximation of Partial Differential Equations. Springer-Verlag, Berlin. Stephansson, 0., Jing, L., Tsang, C.F. (eds.) 1996. Coupled Thermo-Hydro-Mechanical Processes of Fractured Media. Elsevier, Amsterdam. Stephansson, O. (ed.) 2001. DECOVALEX II. Special issue of Int. J. Rock. Mechanics and Mining Sciences 38(1). 

Ohnishi, Y., Shibata, H. Kobayashi, A. 1985. Development of Finite Element Code for the Analysis of Coupled Thermo-Hydro-Mechanical Behaviors of a Saturated-Unsaturated Medium. Proc. Int. Symp. on Coupled Process Affecting the Preformance of a Nuclear Waste Repository. Berkeley pp.263-268. 

VERIFICATION AND VALIDATION OF A THREE-DIMENSIONAL FINITE-ELEMENT CODE FOR COUPLED THERMO-HYDRO-MECHANICAL AND SAUNITY (T-H-M-C) MODELLING IN FRACTURED ROCK MASSES... 

The six verification tests presented in this paper, along with other verification tests presented in the cited literature, have established the ability of the MOTIF finite-element code to accurately solve the equations of groundwater flow, solute and heat transport, and coupled thermo-hydro-mechanical phenomena in porous media, or in fractured media that can be adequately characterized by equivalent porous media (EPM) elements or a combination of EPM and discrete fracture elements. 

Rutqvist, J., Follin, S., Khair, K., Nguyen, S. and Wilcock, P. 1996. Experimental investigation and mathematical simulation of a borehole injection test in deformable rocks. In Coupled Thermo-Hydro-Mechanical Processes of Fractured Media,... 

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