By Lynda Myer
Worldsensing, an IoT remote monitoring company, revealed a smart lining tunnel monitoring solution at the World Tunnel Congress 2022 in Copenhagen this week.
Providing a major safety challenge in the building of tunnels and allowing engineers to make data-driven decisions from as early as the lining construction phase, are the advantages of this system. Embedding sensor equipment within the concrete segments installed by the TBM, this innovation caused avoiding the costly delays of equipment installation and de-installation. At the same time, these sensors also allow engineering teams to get real-time data on lining stability from before the tunnel linings are installed. Considering that the data is transmitted throughout the life of the lining, they can be analyzed using any industry-standard visualization software, improving engineers’ ability to make data-driven decisions relating to infrastructure safety and integrity.
Including a Worldsensing five-channel data logger, the monitoring units are connected securely to vibrating wire sensors such as strain gauges or pressure cells. The data loggers are housed in a polymer casing that can be embedded directly in concrete, with the casing sitting flush with the inner surface of the tunnel lining.
In order to present a real-time view of tunnel stability from the moment the lining is applied, over the construction process the data logger can send signals to a gateway installed up to 100m away in the head of the TBM, whereas it is also powered by batteries that can last up to a decade without maintenance.
This data transmission distance is limited by interference from the TBM. Once the boring machine has moved on, communications can switch to tunnel-based gateways up to 3km in a straight line or 800m around curves.
According to Worldsensing director of global sales Matthieu Laville: ” The system was a major step forward in tunnel boring safety and efficiency. We can now drastically reduce the delays involved in installing and configuring tunnel monitoring systems, saving time and costs. Because the technology is completely based on wireless there is no need for costly and time-consuming cabling and splicing work once the TBM has moved on.”
The amount of reduction in construction time and effort by embedding monitoring solution is up to 25%, as Worldsensing estimates. Additionally, other types of construction, such as building or installing shafts, concrete slabs, bridge pillars, segmental bridges, diaphragm wells, precast foundations, and columns and beams, can also benefit this concept.
