M2 Ground — Tunnel Sentinel

Monitoring chainage 0+685

0+000m1+000

Face chainage 0+780

0+000m1+000

Excavation stage (Step 1)

Construction activity near section

Crown settlement 24

0mm (down)150

Horizontal convergence 32

0mm150

Invert heave 4

0mm (up)50

Loose fall observed

Cracking sound heard

Fresh rock fracture

Crown scaling

New seepage

Muddy / turbid water

Support health (Step 6)

Steel rib

Shotcrete

Rock bolts

Crown support movement

Additional props installed

Seepage condition

Operator

Reading date / time

TARP: RED

—

Baseline (T0) — never overwritten not set

Crown RL Span L–R Tunnel area

No baseline recorded for this section.

Convergence: 32 mm Crown settlement: 24 mm Convergence rate: 11 mm/day

Convergence—

Crown settlement—

Invert heave—

Support condition—

Derived Parameters — Monitoring Section 0+685 —

Distance from face—

Settlement rate—

Settlement accel—

Convergence rate—

Convergence accel—

Invert heave—

Invert rate—

Invert accel—

Excavation stage—

Activity near section—

Time since first abnormality—

Since first seepage—

Since first loose fall—

Since first support deformation—

Unexplained post-excavation movement—

Readings recorded against the selected chainage in the common observation record

Deterioration History — Ch. 0+685 0 records

Timeline built from the shared observation record · Records persist in this browser

ITA guidance — monitoring designed around failure mechanism, baseline data, and acceleration review · Interpretation must respect project TARP values, not generic thresholds · Limitation: deformation monitoring is not a universal prediction system — brittle mechanisms (face instability, rock-burst behaviour) may occur without prior measurable displacement (spec STEP 15)

Ground Stability & Deterioration Monitor