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A new hydro-mechanical model for bentonite resaturation applied to the SEALEX experiments

  • K. E. Thatcher
  • A. E. Bond
  • P. Robinson
  • C. McDermott
  • A. P. Fraser Harris
  • S. Norris
Thematic Issue
Part of the following topical collections:
  1. DECOVALEX 2015

Abstract

Bentonite barriers perform safety critical functions in many radioactive waste disposal concepts, but it is challenging to accurately predict bentonite resaturation behaviour in repository settings. Coupled models of the hydro-mechanical response of bentonite are used to demonstrate understanding of bentonite behaviour in experiments and to predict the response of bentonite in a repository environment. Following trials of a range of numerical approaches, a new model is presented, referred to as the Internal Limit Model, which makes use of key observations on limiting stresses supported in bentonite samples in experimental data. This model is based on the Modified Cam Clay model, and uses the observation that for a given dry density of bentonite, there is a limiting stress that the sample can support, be that stress due to swelling, compaction or suction, to explicitly couple the hydraulic and mechanical models. The model is applied to experimental data from the SEALEX experiments, involving a 70/30 by mass mixture of MX80 bentonite and sand. The model is able to reproduce the experimental data using a single set of parameters for all the experiments considered. This builds confidence that the model will be useful in the future for predictive modelling given appropriate data to characterise the bentonite material being used.

Keywords

Bentonite Coupled modelling Resaturation 

Notes

Acknowledgments

This work was conducted within the international DECOVALEX Project (http://www.decovalex.org), with funding from Radioactive Waste Management Limited (RWM) (http://www.nda.gov.uk/rwm), a wholly–owned subsidiary of the Nuclear Decommissioning Authority.

Supplementary material

12665_2016_5741_MOESM1_ESM.docx (52 kb)
Supplementary material 1 (DOCX 51 kb)

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Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  • K. E. Thatcher
    • 1
  • A. E. Bond
    • 1
  • P. Robinson
    • 1
  • C. McDermott
    • 2
  • A. P. Fraser Harris
    • 2
  • S. Norris
    • 3
  1. 1.Quintessa LtdWarringtonUK
  2. 2.University of EdinburghEdinburghUK
  3. 3.Radioactive Waste Management LimitedDidcotUK

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