Analysis of the FEBEX multi‐barrier system including thermoplasticity of unsaturated bentonite |
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| Authors: | Fabrice Dupray Bertrand François Lyesse Laloui |
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| Institution: | 1. Laboratory of Soil Mechanics, Swiss Federal Institute of Technology, Lausanne (EPFL), , 1015 Lausanne, Switzerland;2. Building, Architecture & Town Planning Department, Université Libre de Bruxelles, , 1050 Bruxelles, Belgium |
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| Abstract: | Deep geological repository involving a multibarrier system constitutes one of the most promising options for isolating high‐level radioactive waste from the human environment. To certify the efficiency of waste isolation, it is essential to understand the behaviour of confining geomaterial under a variety of environmental conditions. To this end, results from a near‐to‐real experiment, the full‐scale engineered barriers in situ experiment, are studied by means of a thermo–hydro–mechanical finite element approach, including a consistent thermoplastic constitutive model for unsaturated soils. Laboratory tests are simulated to calibrate model parameters. The results of the numerical simulations are compared with sensor measurements and show the ability of the model to reproduce the main behavioural features of the system. The influence of the hysteretic and temperature‐dependent retention of water on the mechanical response is exhibited. Finally, those results are interpreted in the light of thermoplasticity of unsaturated soils, which reveals the highly coupled and non‐linear characters of the processes encountered. Copyright © 2011 John Wiley & Sons, Ltd. |
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| Keywords: | thermoplasticity unsaturated soils thermo– hydro– mechanical processes nuclear waste disposal bentonite |
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