| Numerical analysis is often used for examining underground excavations, especially under severeground conditions where rock failure such as rockburst, swelling, or squeezing may occur. Perfectlyplastic material models are most commonly used in determining rock failures around excavationseven though most rocks exhibit brittle and softening behavior in their post-peak regime. In this study,an analysis was made on the influence of post-peak strength of an in-situ rockmass on the growth offailed zone and stability of failure during underground excavation. Brittle, less-brittle and plasticmaterials are used in the finite difference study. The results showed that for the strain-softeningmaterials: (1) A larger failed zone is formed in brittle material than plastic material, and the failedarea is dependent on the brittleness of the material. (2) Unstable failure such as rockburst occurs in themodels and can be examined using numerical measures in the explicit model. |
