Modelling size effect on rock aggregates strength using a DEM bonded-cell model

Yoshiro Huillca, Matías Silva, Carlos Ovalle, Juan Carlos Quezada, Sergio Carrasco, Gabriel Eduardo Villavicencio

Research output: Contribution to journalArticlepeer-review

15 Scopus citations


Empirical evidence has shown that particle breakage affects the mechanical behaviour of granular materials. The source of this mechanism takes place at the particle scale, and the main consequence on the macromechanical behaviour is increasing compressibility. Due to the inverse correlation between particle size and particle crushing strength, coarse rockfill materials are particularly vulnerable to mechanical degradation due to particle breakage. However, such coarse materials do not fit in standard laboratory devices, and the alternative of large sample testing is usually unavailable or too expensive. Alternatively, recent works have proposed multi-scale approaches using the discrete element method (DEM) to carry out numerical testing of coarse crushable materials, although few studies have focused on size effects. This article presents the application of a DEM bonded-cell model to study particle size-strength correlation on angular rock aggregates. Each particle is modelled by a cluster of perfectly rigid polyhedral cells with Mohr–Coulomb contact law. Constant cell density within particles implies that the presence of potential fragmentation planes increases with size. Therefore, particle strength decreases with size. A comprehensive sensitivity analysis was carried out through 1477 particle crushing simulations in a given particle size. Based on published experimental data on calcareous rock aggregates, part of the simulations were used for calibration, and 97 additional simulations of a coarser size fraction were performed for validation. The results show a good agreement with the empirical data in terms of size effect and data scatter through Weibull statistics.

Original languageEnglish
Pages (from-to)699-709
Number of pages11
JournalActa Geotechnica
Issue number3
StatePublished - Mar 2021


  • Bonded-cell model
  • Discrete element method
  • Particle crushing
  • Size effect
  • Weibull distribution


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