TUNNEL CRITICAL SECTION MONITORING
Tunnel
convergence,
measured continuously
A compact optical sensor that tracks the same prisms in your tunnel and reports sub-millimetre displacement to the cloud every 5 minutes. It fits where an automated total station can’t, and it runs without site visits.
Plan a monitoring section
Read the UK case study
≤2 mm
Agreement with an automated total station in a live UK tunnel
>95%
Uptime across three months of unattended monitoring
0
Manual site visits needed during the deployment
5 min
Between readings, around the clock
WHERE IT’S USED
Built for the tunnels you can’t close for long
Metro & railway tunnels
Watch lining convergence and lateral movement while adjacent excavation, piling or dewatering changes the ground around an operational line.
Road tunnels
Watch lining convergence and lateral movement while adjacent excavation, piling or dewatering changes the ground around an operational line.
Utility & service tunnels
Monitor tight, hard-to-reach galleries where a total station is not set up, with LTE-M or Ethernet connectivity depending on what’s available underground.
Automated total stations are the established solution for continuous monitoring, but they require sufficient space, regular maintenance, and ongoing site attention.
THE OPERATOR’S PROBLEM
Continuous monitoring shouldn’t cost you a possession every month
Nearby works change the stress state of the subsoil, and your obligations don’t pause while they correct foundations. Traditional instruments make continuous monitoring harder than it needs to be.
Clearance is non-negotiable
Bulky equipment inside a live tunnel competes with the vehicle or train envelope.
Every maintenance visit is a shutdown
Each calibration trip means a site visit, a permit and a safety plan.
The critical sections are the tightest
Monitoring from a position where an instrument fits, not necessarily where the risk is greatest.
HOW IT WORKS
One sensor, one cross section, every 5 minutes
TotaLite photographs standard survey prisms and converts sub-pixel changes in the image into displacement. Convergence is computed automatically between the target pairs you define.
TotaLite sensor • Field of view • Prism pairs
Typical: 5 prisms per cross-section · min. 2° separation
Prisms on the lining
The same standard survey prisms you’d use with a total station, fixed toward the sensor. Typically five per section.
Sensor on a bracket
Mounted rigidly, powered on site, and set up in about an hour. One sensor measures 15–25 targets at once.
Readings in the cloud
Relative displacement arrives on the TotaLite platform every 5 minutes, with alert thresholds set on each chart.