Although tunnel construction monitoring can generally be regarded as a special type of construction-site monitoring, it does exhibit a number of characteristics that make it a unique case. In this type of construction, the safety of the respective structure plays a far greater role than it does for other structures.
Structural subsidence and the consequent possibility of structural collapse constitute a crucial problem for workers, not to mention the potentially high costs of the machines being used (…), from a system perspective, it is also essential that monitoring is carried out simultaneously at a series of points along a very long stretch, where a local power source may not always be available, and monitoring data is gathered for overall vibrations, for all alerts in the case of particularly severe events, and that such data is available at all times. To achieve this, it is necessary to have direct access to the measurement instruments, often an impossibility to use[…]
Against this backdrop, the GEA system is the ideal solution. Multiple sensors can be placed simultaneously from a single central unit across a very large area of up to 2 kilometers in diameter. Each sensor is powered by the same cable that is used for data transmission. This in turn wards off possible drawbacks that might result from lack of a local power supply. Thus the central unit can be installed in a safe location with adequate protective systems and a backup in case electricity is not available. Remote control is assured by modern systems such as routers and/or LAN connections. Moreover, even in the absence of a connection, the station can activate backup systems in auto mode, thanks to output relays that can be managed using various logics, depending on the monitoring point.