Cavity expansion tests were simulated using the discrete element method (DEM), where a two-dimensional bonded particle model was validated to investigate the initiation of tensile fracture and breakdown (peak) pressure. The effect of far-field stress, as well as borehole size, on cavity expansion of rock was studied; specimens with three different sizes under various levels of far-field stresses were tested numerically. It is evident that an increase in borehole size results in a lower breakdown pressure. Furthermore, it is illustrated that the breakdown pressure increases with the decrease of the deviatoric component of the stress state, regardless of specimen size. As the far-field stress approaches the hydrostatic condition, the size effect on breakdown pressure reduces. The stress state affects the brittleness of the system, modifying the transition between strength-driven and energy-driven failure.
|Original language||English (US)|
|Number of pages||11|
|State||Published - 2017|
|Event||15th International Conference of the International Association for Computer Methods and Advances in Geomechanics, IACMAG 2017 - Wuhan, China|
Duration: Oct 19 2017 → Oct 23 2017
|Conference||15th International Conference of the International Association for Computer Methods and Advances in Geomechanics, IACMAG 2017|
|Period||10/19/17 → 10/23/17|
Bibliographical noteFunding Information:
This research was partially funded by the China Scholarship Council (CSC) and the MSES/Miles Kersten Chair. Professor Ali Fakhimi from New Mexico Institute of Mining and Technology allowed access to his CA2 program.
© 2017 15th International Conference of the International Association for Computer Methods and Advances in Geomechanics
Copyright 2020 Elsevier B.V., All rights reserved.
- Bonded-particle model
- Breakdown pressure
- Cavity expansion
- Far-field stress