Urban tunnel projects fail reviews when staging is implicit. Reviewers need to see how ground support, face pressure, and lining stiffness evolve relative to measured settlement bowls.
Our standard FLAC3D staging sequence:
• Phase 0 — K0-equilibrated initial stress with groundwater table verified
• Phase 1 — Heading advance with face pressure tied to EPB/BT assumptions
• Phase 2 — Primary support activation (shotcrete, bolts) with staged stiffness
• Phase 3 — Lining installation and long-term creep if applicable
• Phase 4 — Building and utility sensitivity at surface monitoring points
Document constitutive softening limits and when they activate. Pair each stage with instrumentation expectations so field teams know what "normal" looks like before the first ring is installed.