Infrastructure
Zheleznitsa Tunnel
- Year
- 2019-2024
- Location
- Struma Motorway, Lot 3.3
- Client
- NKSIP
- Our role
- Geodetic survey, reference network, staking, bore control, as-built documentation
About the project
Zheleznitsa Tunnel is part of Struma Motorway, Lot 3.3 — one of the most complex engineering projects executed in Bulgaria in recent years. The two parallel tunnel tubes pass through complex geological conditions and require exceptional geodetic accuracy.
Our role
- Reference geodetic network — establishing and maintaining a precision network in and around the tunnel;
- Bore control — monitoring tunnel boring machines and ensuring correct meeting of the two bores;
- Geometric measurements — cross-section, convergence and deformation control during construction;
- As-built documentation — drawings, BIM model, documentation for acceptance acts.
Technologies
- 3D laser scanning of cross-sections;
- Precision total stations for underground measurements;
- Precision geometric level for height control;
- GNSS reference network on surface above the alignment.