Air quality monitoring in a tunnel

Project

Boring of a tunnel in the T3A section of Grand Paris Express metro between the Pont de Sèvres and Issy-Vanves-Clamart stations.

Challenge

Air sensors had already been installed when works began about 2 years ago. The cline (Horizon – T3A joint venture) wanted to add CO₂ level monitoring as legal limits had been lowered on 1st July 2020. Client can monitor the efficiency of ventilation in the tunnel so as to limit how much workers are exposed to specific gas in the tunnel.

Need: track CO₂ levels.

UBY solution

Installation and connection to UBY Environment platform beginning October 2020 until 2024 – 2025 when works are forecast to end. 8 hour and 15 minute average exposure limits have been set as alert thresholds on the platform.
Worksite receives alerts when these thresholds are exceeded.

Our sensors also record levels of BTX (benzene, toluene, xylene) thanks to the PID sensor. A suspicion of one of these compounds must then be confirmed by chemical-reacting tubes.

Levels of various gases, dust and VOCs are monitored as the tunnel is bored and our solution helps the worksite make sure ventilation and preventative measures are in place.