Tunnel and underground structure scanning
3D laser scanning of metro, road and hydraulic tunnels, collectors, shafts and basements: cross-sections, deformation and clearance analysis.
Tunnels, collectors, shafts and other underground structures are among the hardest objects to survey because of confined space, poor lighting and the absence of GNSS. A laser scanner needs no light and records the entire inner surface of a tunnel from a single station at millimetre level, greatly reducing the time staff spend in hazardous areas.
Scans are tied to an underground traverse network transferred into the tunnel by total station, and in long tunnels they are combined with SLAM or mobile scanning systems. Cross-sections at any interval are cut from the point cloud, the as-built profile is compared with the design, and ovality, settlement and deformation are shown on colour-coded maps. Typical relative accuracy is ±2–5 mm.
The service is used to control excavation and lining in tunnels under construction, for periodic monitoring of operating metro and road tunnels, clearance checks and refurbishment design. In Baku we also carry out as-built surveys of utility collectors, basements and industrial shafts. Repeat scans make it possible to track changes over time with precision.
When you need it
- Checking excavation and lining against design
- Periodic monitoring of metro and road tunnels
- Clearance and kinematic envelope checks
- As-built surveys of collectors and underground utilities
- Surveys of shafts and underground mine workings
- Base data for repair and strengthening design
What's included
- Underground traverse and control network
- Tunnel capture with terrestrial, SLAM or mobile scanning
- Scan registration and georeferencing
- Cross-sections at a specified interval
- Comparison of as-built and design profiles
- Deformation and ovality maps
How we work
- Site visit and agreement on safety requirements
- Transfer of the control network into the tunnel
- Laser scanning
- Processing, cross-sections and comparison analysis
- Delivery of report and drawings
Deliverables
- Georeferenced point cloud
- Cross-sections and longitudinal profile (DWG/PDF)
- Deviation-from-design and deformation maps
- Technical report
