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ORIGINAL RESEARCH article

Front. Built Environ.
Sec. Geotechnical Engineering
Volume 11 - 2025 | doi: 10.3389/fbuil.2025.1536760
This article is part of the Research Topic Thermo-hydro-chemo-mechanical applications using the fem software code_bright: a review View all articles

An approach to improve the numerical simulation of crushed salt compaction behavior

Provisionally accepted
Larissa Friedenberg Larissa Friedenberg 1*Sebastia Olivella Sebastia Olivella 2
  • 1 Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) gGmbH, Braunschweig, Germany
  • 2 Universitat Politecnica de Catalunya, Barcelona, Catalonia, Spain

The final, formatted version of the article will be published soon.

    Crushed salt as backfill material in a repository for high-level nuclear waste is aimed to act as a longterm barrier. The sealing effect of crushed salt evolves with ongoing compaction and therefore reduction in porosity and permeability. For a reliable prognosis of the compaction behavior in the longterm, constitutive models are crucial that capture the experimentally observed processes and credibly extrapolate these processes outside the range they were calibrated in. Up to now there is still no constitutive model for crushed salt which is validated against all factors/processes influencing compaction and/or the whole porosity range (especially 𝜑 < 5 %).The constitutive model for crushed salt compaction available in CODE_BRIGHT has been used in the field of repository research for several years. It has been applied in recent research projects on crushed salt compaction, where shortcomings in the modelling of compaction behaviour in dependence on mean stress and deviatoric stress variations are identified. Based on this discovered potential for improvement an approach for the modification of the constitutive model is proposed within this paper. It addresses the assumption of an idealized geometry and network of grains which is introduced by mathematically contraint functions dependent on void ratio. The proposed approach aims to give more flexibility in the handling of geometry dependence. The paper comprises an introduction into the use of crushed salt in the context of nuclear waste repository. The description of the constitutive model for crushed salt available in CODE_BRIGHT is given, as well as, the proposal for improvement and its application. It is finished with a sensitivity study for the new approach followed by a summary and outlook.

    Keywords: Crushed salt, Constitutive Modelling, creep, Backfill material, repository research

    Received: 29 Nov 2024; Accepted: 30 Jan 2025.

    Copyright: © 2025 Friedenberg and Olivella. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Larissa Friedenberg, Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) gGmbH, Braunschweig, Germany

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.