Abstract
Numerical modelling of coupled physical processes in bentonite–sand mixtures under the geological conditions is significant for designing and constructing sealing systems in deep underground repositories for highly radioactive nuclear waste. Within the framework of DECOVALEX 2015, Task A, this work presents the model validation of OpenGeoSys by numerical modelling of coupled hydromechanical (HM) processes in bentonite–sand mixtures. Parameters used in the HM model were determined by modelling the laboratory tests of the sealing experiment (SEALEX). Afterwards these parameters were applied for the modelling of a small-scale mock-up test considering the influence of technological gap and incidental fail of the seal in the sealing system. In order to investigate the availability of employing these HM parameters and numerical models directly to field predictions, the modelling results and measured data of an in situ SEALEX experiment were analysed comparatively. The modelling results reproduced well the main features in HM behaviour of the compacted bentonite–sand mixture, which denotes that the adopted HM models and parameters are adequate for describing the HM processes in the sealing system. It is necessary to take the elastoplastic behaviour and evolution of the permeability of bentonite–sand mixtures into account when using the adopted models to reproduce the HM processes of a sealing system.
Similar content being viewed by others
References
Alonso EE, Gens A, Josa A et al (1990) Constitutive model for partially saturated soils. Géotechnique 40(3):405–430
Alonso EE, Gens A, Gehling WY (1994) Elastoplastic model for unsaturated expansive soils. In: Proceedings of the 3rd European conference on numerical methods in geotechnical engineering, Manchester, pp 11–18
Alonso EE, Vaunat J, Gens A (1999) Modelling the mechanical behaviour of expansive clays. Eng Geol 54(1):173–183
Barnichon F, Deleruyelle JD (2009) Sealing experiments at the Tournemire URL. Towards convergence of technical nuclear safety practices in Europe, EUROSAFE
Barnichon JD, Dick P, Bauer C, et al (2011) The sealex in situ experiments: performance tests of repository seals. In: 12th ISRM Congress. International society for rock mechanics
Chen YG, Cui YJ, Tang AM, Wang Q, Ye WM (2014) A preliminary study on hydraulic resistance of bentonite/host-rock seal interface. Géotechnique 64(12):997–1002
Cui YJ, Tang AM, Loiseau C, Delage P (2008) Determining water permeability of compacted bentonite-sand mixture under confined and free-swell conditions. Phys Chem Earth 33:S462–S471
Daupley X (1997) ÉTUDE DU POTENTIEL DE L’EAU INTERSTITIELLE D’UNE ROCHE ARGILEUSE ET DE RELATIONS ENTRE SES PROPRIETES HYDRIQUES ET MECANIQUES Application aux argilites du Toarcien de la région de Tournemire(Aveyron). Ph.D. thesis, Travaux Universitaires
Delage P, Howat MD, Cui YJ (1998) The relationship between suction and swelling properties in a heavily compacted unsaturated clay. Eng Geol 50(1):31–48
Dixon DA, Martino JB, Vignal B, Masumoto K, Fujita T (2007) Overview of the evolution, performance and state of a bentonite-based tunnel seal after 5 years of operation. Phys Chem Earth Parts A/B/C 32(8):741–752
Gens A, Alonso EE (1992) A framework for the behaviour of unsaturated expansive clays. Can Geotech J 29(6):1013–1032
Gens A, Vállejan B, Sánchez M, Imbert C, Villar M, Van GM (2011) Hydromechanical behaviour of a heterogeneous compacted soil: experimental observations and modelling. Géotechnique 61(5):367–386
Hoffmann C, Alonso EE, Romero E (2007) Hydro-mechanical behaviour of bentonite pellet mixtures. Phys Chem Earth Parts A/B/C 32(8):832–849
Hou JJ, Qiao L, Cai QC, Li Z (2014) Study on compression resistance under different confining pressures and parameters of cam-clay model of bentonite. In: Huang Y (ed) Applied mechanics and materials, vol 501. Trans Tech Publications, Swizterland, pp 430–433
Kolditz O, Bauer S, Bilke L, Böttcher N, Delfs J-O, Fischer T, Görke UJ, Kalbacher T, Kosakowski G, McDermott CI et al (2012) Opengeosys: an open-source initiative for numerical simulation of thermo-hydro-mechanical/chemical (thm/c) processes in porous media. Environ Earth Sci 67(2):589–599
Lewis RW, Schrefler BA (1982) A finite element simulation of the subsidence of gas reservoirs undergoing a water drive. Finite Elem Fluids 4:179–199
Lloret MA, Villar MV, Sanchez M, Gens SA, Pintado LX, Alonso EE (2003) Mechanical behaviour of heavily compacted bentonite under high suction changes. Geotechnique 53(1):27–40
Martino JB, Dixon DA, Kozak ET, Gascoyne M, Vignal B, Sugita Y, Fujita T, Masumoto K (2007) The tunnel sealing experiment: an international study of full-scale seals. Phys Chem Earth Parts A/B/C 32(1):93–107
Mašín D (2013) Double structure hydromechanical coupling formalism and a model for unsaturated expansive clays. Eng Geol 165:73–88
Mata MC (2003) Hydraulic behaviour of bentonite based mixtures in engineered barriers: the backfill and plug test at the Äspö Hrl (Sweden). Universitat Politècnica de Catalunya
Millard A, Mokni N, Barnichon JD, Thatcher KE, Bond AE, Fraser-Harris A, Dermott CMc, Blaheta R, Michalec Z, Hasal M et al (2016) Comparative modelling of laboratory experiments for the hydro-mechanical behaviour of a compacted bentonite-sand mixture. Environ Earth Sci 75(19):1311
Millard A, Mokni N, Barnichon JD, Thatcher K, Bond A, Fraser-Harris A, Dermott CMc, Blaheta R, Michalec Z, Hasal M, Nguyen TS, Nasir O, Yi H, Kolditz O (2017) Comparative modelling approaches of hydro-mechanical processes in sealing experiments at the tournemire URL. Environ Earth Sci 76(2):78
Nasir O, Nguyen TS, Barnichon JD, Millard A (2017) Simulation of the hydro-mechanical behaviour of bentonite seals for the containment of radioactive wastes. Can Geotech J 54(8):1055–1070
Romero E, Villar MV, Lloret A (2005) Thermo-hydro-mechanical behaviour of two heavily overconsolidated clays. Eng Geol 81(3):255–268
Rutqvist J, Ijiri Y, Yamamoto H (2011) Implementation of the barcelona basic model into tough-flac for simulations of the geomechanical behavior of unsaturated soils. Comput Geosci 37(6):751–762
Saba S (2013) Hydro-mechanical behaviour of bentonite-sand mixture used as sealing materials in radioactive waste disposal galleries. Ph.D. Thesis, Université Paris-Est
Saba S, Delage P, Lenoir N, Cui YJ, Tang AM, Barnichon JD (2014a) Further insight into the microstructure of compacted bentonite-sand mixture. Eng Geol 168:141–148
Saba S, Barnichon JD, Cui YJ, Tang AM, Delage P (2014b) Microstructure and anisotropic swelling behaviour of compacted bentonite/sand mixture. J Rock Mech Geotech Eng 6(2):126–132
Sun DA, Sheng DC, Sloan SW (2007) Elastoplastic modelling of hydraulic and stress–strain behaviour of unsaturated soils. Mech Mater 39(3):212–221
Sun WJ, Sun DA (2012) Coupled modelling of hydro-mechanical behaviour of unsaturated compacted expansive soils. Int J Numer Anal Methods Geomech 36(8):1002–1022
Tang AM, Cui YJ (2010) Effects of mineralogy on thermo-hydro-mechanical parameters of mx80 bentonite. J Rock Mech Geotech Eng 2(1):91–96
Villar MV, García-Siñeriz JL, Bárcena I, Lloret A (2005) State of the bentonite barrier after five years operation of an in situ test simulating a high level radioactive waste repository. Eng Geol 80(3):175–198
Villar MV, Martín PL, Bárcena I, García-Siñeriz JL, Gómez-Espina R, Lloret A (2012) Long-term experimental evidences of saturation of compacted bentonite under repository conditions. Eng Geol 149:57–69
Wang Q, Tang AM, Cui YJ, Delage P, Barnichon JD, Ye WM (2013a) The effects of technological voids on the hydro-mechanical behaviour of compacted bentonite-sand mixture. Soils Found 53(2):232–245
Wang Q, Cui YJ, Tang AM, Barnichon JD, Saba S, Ye WM (2013b) Hydraulic conductivity and microstructure changes of compacted bentonite/sand mixture during hydration. Eng Geol 164:67–76
Wang Q, Tang AM, Cui YJ, Barnichon JD, Ye WM (2013c) A comparative study on the hydro-mechanical behavior of compacted bentonite/sand plug based on laboratory and field infiltration tests. Eng Geol 162:79–87
Wang Q, Tang AM, Cui YJ, Barnichon JD, Ye WM (2013d) Investigation of the hydro-mechanical behaviour of compacted bentonite/sand mixture based on the bexm model. Comput Geotech 54:46–52
Ye WM, Cui YJ, Qian LX, Chen B (2009) An experimental study of the water transfer through confined compacted gmz bentonite. Eng Geol 108(3):169–176
Yong RN, Boonsinsuk P, Wong G (1986) Formulation of backfill material for a nuclear fuel waste disposal vault. Can Geotech J 23(2):216–228
Acknowledgements
This research was supported by the UFZ and the China Scholarship Council (CSC). The authors appreciate and thank the Funding Organisations for their financial and technical support of the DECOVALEX project work described in this paper.
Author information
Authors and Affiliations
Corresponding author
Additional information
This article is part of a Topical Collection in Environmental Earth Sciences on “DECOVALEX 2015”, guest edited by Jens T Birkholzer, Alexander E Bond, John A Hudson, Lanru Jing, Hua Shao and Olaf Kolditz.
Rights and permissions
About this article
Cite this article
Yi, H., Wang, W., Kolditz, O. et al. Hydromechanical modelling of the SEALEX experiments. Environ Earth Sci 76, 737 (2017). https://doi.org/10.1007/s12665-017-7080-0
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s12665-017-7080-0