Tunnels play an important part in our world, whether they are short, busy ways to connect parts of a city or long constructions like the tunnels that are built to serve as an alternative to mountain passes and burrow right through part of a mountain range.

Some tunnels are blasted through solid rock, but many others are constructed through soil deposits and are therefore subject to the effects of ground movement. For this reason, the engineers responsible for constructing and maintaining these excavations must have measures in place for monitoring ground movement in tunnels.

Unchecked and unnoticed ground movement can put the stability of the tunnel at risk, so it is vital that all tunnels are monitored using the correct equipment, so action can be taken if a potentially risky situation starts to develop within the tunnel.

The MDT SMART GMM (Ground Movement Monitor) is a useful instrument when it comes to monitoring ground movement in tunnels. The SMART GMM is a cost-effective solution that is also quick and easy to install (no grouting is required). It is simply threaded onto a rock bolt, which is then placed into a standard borehole (35mm or bigger).

To make the SMART GMM even more versatile and useful as a tool for monitoring ground movement in tunnels, it can also be monitored wirelessly, for example by being linked up to a comprehensive geotechnical monitoring system like the Loadsensing LS-GS system.

The LS-G6 can monitor a large array of GMMs, along with other geotechnical monitoring instruments, hydrology sensors and other devices used to monitor tunnels, as well as other excavations and civil engineering projects.