Monitoring of the newly built Nesima-Misterbianco tunnel with TBM technology and monitoring of the upgrading and transformation of the railway in the urban areas of Catania and Misterbianco.

Location: Nesima-Misterbianco (First Lot)
Client: CMC Cooperativa di Muratori e Cementisti di Ravenna
Duration of monitoring service: 36 months

The “OF Tunnel” system was installed to monitor:

  • the state of tension and deformation of the tunnel segments,
  • the convergence measurements of four tunnel sections,
  • the measurement of longitudinal deformations of the tunnel, caused by thrusts due to the surrounding soil.

The sensors are embedded in the ashlars during their production phase, which also allows monitoring of the ashlar curing process.

Four convergence measurement sections are installed on traditionally built tunnel sections, the sensors are anchored to the reinforcement of the structure and embedded in the concrete used for the tunnel construction. The sensors for the longitudinal measurements are not embedded in the structure, but placed  outside, this is done after the construction of the specific tunnel section.

The measurements are carried out at a frequency of one data per second from each sensor at the same time, three hundred sensors are installed and connected through 3 km of optical fibre laid, three hundred data per second is acquired by the H24-365D operating system.

The measurement technique applied is the semi-distributed one ,with deformation and temperature sensors connected to a single optical interrogator on which the Edgegateway software is installed for real-time analysis of the quantities monitored.

NTSG supported the customer in the analysis of the data and the maintenance of the system, providing the customer with a web interface to view and control the measurements acquired by the system and the alarms recorded.


300 sensors installed
3 km of optical fibre
Approximately 60 days days to install the system
300 data per second