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Effects of Pore Pressure on Failure Process and Acoustic Emissions of Rock Specimen with Pre‐existing Random Imperfections
Simulation Using FLAC and FISH Functions
For a rock specimen under a constant confining pressure and variant pore pressures, with initially random material imperfections, the failure process and acoustic emissions in plane strain compression are numerically modeled using FLAC. The effect of pore pressure is represented in FLAC by the incorporation of an effective stress. For the intact rock element exhibiting linear strain‐softening behavior beyond the occurrence of failure and then ideal plastic behavior, the failure criterion is a composite Mohr‐Coulomb criterion with tension cut‐off. The initial imperfection undergoes ideal plastic behavior beyond the occurrence of failure. After the rock specimen is subjected to pore pressure and confining pressure reaches an equilibrium state, a displacement‐controlled loading is applied in axial direction. As pore pressure increases, the accumulated number of acoustic emissions corresponding to the peak stress rises; the acoustic emissions in the vicinity of the peak stress become intensive; and the accumulated number of acoustic emissions when the residual stage is reached increases. These numerical results suggest that the precursors to failure are more apparent at higher pore pressures. The peak of the maximum unbalanced force appears in the strain‐softening stage and it decreases with an increase of pore pressure.
Effects of Pore Pressure on Failure Process and Acoustic Emissions of Rock Specimen with Pre‐existing Random Imperfections
Simulation Using FLAC and FISH Functions
For a rock specimen under a constant confining pressure and variant pore pressures, with initially random material imperfections, the failure process and acoustic emissions in plane strain compression are numerically modeled using FLAC. The effect of pore pressure is represented in FLAC by the incorporation of an effective stress. For the intact rock element exhibiting linear strain‐softening behavior beyond the occurrence of failure and then ideal plastic behavior, the failure criterion is a composite Mohr‐Coulomb criterion with tension cut‐off. The initial imperfection undergoes ideal plastic behavior beyond the occurrence of failure. After the rock specimen is subjected to pore pressure and confining pressure reaches an equilibrium state, a displacement‐controlled loading is applied in axial direction. As pore pressure increases, the accumulated number of acoustic emissions corresponding to the peak stress rises; the acoustic emissions in the vicinity of the peak stress become intensive; and the accumulated number of acoustic emissions when the residual stage is reached increases. These numerical results suggest that the precursors to failure are more apparent at higher pore pressures. The peak of the maximum unbalanced force appears in the strain‐softening stage and it decreases with an increase of pore pressure.
Effects of Pore Pressure on Failure Process and Acoustic Emissions of Rock Specimen with Pre‐existing Random Imperfections
Simulation Using FLAC and FISH Functions
Shao, Jian‐Fu (editor) / Burlion, Nicolas (editor) / Wang, X. B. (author)
2013-02-19
10 pages
Article/Chapter (Book)
Electronic Resource
English
| British Library Online Contents | 2007
| British Library Conference Proceedings | 2008
| British Library Conference Proceedings | 2007
| British Library Online Contents | 2015