Engineer Configuration — TARP Trigger Values

Editing project-wide defaults. Enter a chainage and load to override for one zone.
Applied to the 24-hour % change in seepage discharge (Module 3).
Heavy rainfall alone flags deterioration — the seepage response typically lags the rainfall by hours (Module 3).
Adequacy below these values triggers the TARP state (Module 1).
Minimum return-air velocities (BS 6164) that drive the Q₂ dust/fumes and Q₃ methane airflow requirements in Module 1.
A measured gas event at or above Red triggers RED; at or above Amber (below Red) triggers AMBER. A gas event with no reading is treated as worst case (RED). Enter values from the project's approved TARP / statutory criteria (DGMS).
A loose fall whose quantity bucket is at or above the major threshold → RED. That many loose falls within the window days → RED. A gas event within the gas window days → RED (or AMBER per ppm thresholds).
Values apply immediately to all modules' TARP logic.
Where these values come from

Trigger levels depend on tunnel geometry, geology, overburden, support system, expected ground behaviour, design analysis, construction stage, baseline movement, and the approved method statement. Enter the values from the project's approved TARP / design — not generic defaults.

Zone overrides: enter a chainage (e.g. 0+685) and load. A zone override only replaces the fields you change — others inherit the project values.

Observational triggers (loose fall, rib buckling, cracking + movement) are not threshold-based and always override numerical values, per Step 15.

Data freshness is itself monitored: if the last reading is older than the configured limit, TARP degrades to AMBER — "safety status unconfirmed" (Step 17).

ITA guidance — monitoring layout and interpretation based on predicted ground/structural mechanism and critical areas, not generic instrumentation · Spec Module 2, Steps 14–17