FLAC simulates the four excavation stages and three construction steps within each stage for a multistage tunnel excavation and construction. The convergence-confinement method is used to simulate the effect of the tunnel advance. A ground reaction curve is calculated to relate the effect of the advancing tunnel face to reduction in internal pressure within the excavated region. Both rockbolt support and a shotcrete liner are installed at different stages of the tunnel advance.
Keywords:
- Multistage excavation
- shallow tunnel
- rockbolts
- Shortcrete
- Ground reaction curve
- Mohr-Coulomb model
Materials:
- Concrete
- Rock
- Steel
Analyses:
- Static