Keeping a tunnel construction safe
How automated monitoring watched over the M85 motorway tunnel in Sopron, and how SURVIOT was born there.
Building the Sopron tunnel
When construction of the M85 Sopron tunnel started in 2020, SDD Consortium, the main contractor, commissioned a construction monitoring system and data processing software to fit their special needs at the Sopron site. This is where SURVIOT was born.
The monitoring requirements set by the design engineer meant extensive manual monitoring. Because of earlier negative experiences with tunnel construction in Hungary, the client also wanted closer oversight than usual. No available system was sensor-agnostic, multi-user and free of IT maintenance at the same time. The decision was made when the cost of monitoring personnel was compared to the SURVIOT licence fee.
Main goals of the monitoring system
- Observe movements of the anchor-reinforced, shotcrete portal structure
- Monitor convergence of the tunnel's concrete wallwork
- Monitor surface movements above the tunnel on Bécs hill
- Integrate data from groundwater monitoring wells
- Monitor buildings above the tunnel
Portal and convergence monitoring
The portal structure is monitored with prisms installed in the shotcrete slope and the surrounding embankment, measured in real time by a robotic total station.
During mining, 5 symmetrically installed prisms in every cross section, every 10 metres, are measured continuously by the preinstalled robotic total station. The total stations connect wirelessly to a central data aggregator, and the data is transmitted to the cloud and into SURVIOT.
52 surface points on Bécs hill
Above the tunnel, 52 surface points are monitored by SURVIOT GNSSPODs using multi-constellation GNSS measurements. The PODs are remotely monitored and need only a periodic battery change. They connect over 2G, 3G and 4G mobile networks using our own protocol.
The heart of each unit is a multi-constellation GNSS receiver with a calibrated antenna. The accuracy of the system has been certified by the Hungarian GNSS Service Centre.
Groundwater and weather data
SURVIOT WellPODs read groundwater levels automatically using piezometric pressure sensors.
A local meteorological station lets engineers correlate weather with movement data and separate movements caused by ground saturation from those caused by construction. Data processing, visualisation, reporting, notifications, statistical and engineering calculations are all done by the SURVIOT platform.
Challenges we overcame
Varied geology
Geological conditions changed along the tunnel.
Rare in Hungary
Tunnel construction is still unusual in the country.
Avoiding accidents
Learning from what happened at the M6 tunnel construction.
Shared decisions
All relevant stakeholders were included in engineering decisions.
Scarce expertise
Experienced labour is hard to find and expensive.
SURVIOT as a software service
With continuous availability, SURVIOT became the single source of monitoring data on site and saved numerous hours of work.
- Surveyor hours saved
- 10k
- Active users
- 54
- Data points
- 220
- Alerts & notifications
- 26k
- Data collected
- 1 GB
Devices built in and used
Prisms cover the whole portal structure and the surrounding slope, 5 in each cross section, every 10 metres.
- Prisms
- 25
- Deep-founded reference points
- 10
- SURVIOT GNSSPODs
- 60
- Robotic total stations
- 2
- SURVIOT WellPODs
- 3
- SURVIOT InclinoPODs
- 8
- Weather station
- 1
Planning a project like this?
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