Comparative verification of hydro-mechanical fracture behavior: Task G of international research project DECOVALEX–2023

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Mostafa Mollaali - , Helmholtz Centre for Environmental Research (Author)
  • Olaf Kolditz - , Chair of Applied Environmental Systems Analysis, Helmholtz Centre for Environmental Research (Author)
  • Mengsu Hu - , Lawrence Berkeley National Laboratory (Author)
  • Chan Hee Park - , Korea Institute of Geoscience and Mineral Resources (Author)
  • Jung Wook Park - , Korea Institute of Geoscience and Mineral Resources (Author)
  • Christopher Ian McDermott - , University of Edinburgh (Author)
  • Neil Chittenden - , Quintessa Ltd (Author)
  • Alexander Bond - , Quintessa Ltd (Author)
  • Jeoung Seok Yoon - , DynaFrax UG (Limited) (Author)
  • Jian Zhou - , Beijing University of Technology (Author)
  • Peng Zhi Pan - , CAS - Wuhan Institute of Rock and Soil Mechanics, University of Chinese Academy of Sciences (Author)
  • Hejuan Liu - , CAS - Wuhan Institute of Rock and Soil Mechanics, University of Chinese Academy of Sciences (Author)
  • Wenbo Hou - , CAS - Wuhan Institute of Rock and Soil Mechanics, University of Chinese Academy of Sciences (Author)
  • Hongwu Lei - , CAS - Wuhan Institute of Rock and Soil Mechanics, University of Chinese Academy of Sciences (Author)
  • Liwei Zhang - , CAS - Wuhan Institute of Rock and Soil Mechanics, University of Chinese Academy of Sciences (Author)
  • Thomas Nagel - , Freiberg University of Mining and Technology (Author)
  • Markus Barsch - , Freiberg University of Mining and Technology (Author)
  • Wenqing Wang - , Helmholtz Centre for Environmental Research (Author)
  • Son Nguyen - , Canadian Nuclear Safety Commission (Author)
  • Saeha Kwon - , Korea Atomic Energy Research Institute (Author)
  • Changsoo Lee - , Korea Atomic Energy Research Institute (Author)
  • Keita Yoshioka - , Helmholtz Centre for Environmental Research, University of Manitoba (Author)

Abstract

Numerical simulations become a necessity when experimental approaches cannot cover the required physical and time scale of interest. One of such area is a simulation of long-term host rock behaviors for nuclear waste disposal and simulation tools involved in the assessment must go through rigorous validation tests. The DECOVALEX project (Development of COupled models and their VAlidation against EXperiments) is dedicated to this purpose by international participants.a This work is part of the ongoing phase DECOVALEX–2023 (D–2023, Task G) particularly aiming to simulate fracture behaviors under various conditions. Here, we cross-verified a variety of numerical methods including continuous and discontinuous approaches against four benchmark exercises with emphasis on numerical accuracy and parameterization of the various numerical approaches. The systematic inter-comparisons of test cases highlight advantages and disadvantages of the different numerical models. Numerical details on discretization effects (e.g. mesh density and orientation) and domain size were investigated in detail for practical applications. It became evident that meticulous attention to mesh resolution and domain size is imperative for achieving accurate numerical simulations, even for static cracks. Moreover, when comparing numerical methods to closed-form solutions for static cracks, all models successfully reproduced the maximum crack opening but encountered challenges near the crack tips. Finally, the paper discusses how to convert between and therefore compare parameters of various numerical approaches. Our benchmark studies reveal that each model necessitates a distinct number of parameters, even in simple scenarios like static crack aperture benchmarks. It is generally more practical to employ fewer parameters to mitigate model over-parameterization and enhance experimental feasibility.

Details

Original languageEnglish
Article number105530
Journal International journal of rock mechanics and mining sciences : RMMS
Volume170
Publication statusPublished - Oct 2023
Peer-reviewedYes

Keywords

Keywords

  • Benchmarking, Code comparison, DECOVALEX–2023, Fracture mechanics, Numerical method