Deformation Monitoring

Deformation Monitoring is Critically Important for Mine Safety

Deformation MonitoringIn the mining context, deformation occurs when sections of ground or rock structures change their shape and/or dimensions. This is usually as a result of stress caused by many factors (e.g. the behaviour of nearby ground, rocks or bodies of water, as well as the effect of mining itself).

Unmanaged deformation can have a catastrophic effect on a mine. Large quantities of soil or rock that suddenly shift and change shape can place so much pressure on a shaft or tunnel that it collapses, endangering the lives of miners, causing damage to mining equipment and leading to a loss of productivity while the affected tunnels or shafts are repaired.

In order to prevent, or at least severely limit, the dangers posed by this phenomenon, it is essential that all mines practice proper deformation monitoring. Accurate and robust geotechnical instruments are widely used by highly-skilled geotechnical engineers to perform this type of monitoring.

Extensometers, like the SMART MPBX, instrumented cable bolts, like the SMART Cable Bolt from MDT, and contractometers, like the SMART Contractometer, are ideally suited for deformation monitoring, as they are sensitive enough to detect deformation in its early stages, but tough enough to not be easily damaged by its effects.

This interesting case study explains how shotcreted pillars were built inside the Golden Giant Mine (Hemlo, Ontario) to provide additional support when it was found that shotcreted ground support and cable bolts were not sufficient.

As this long-established mine spread outwards, a lot of the mining occurred under and within fairly unstable rock mass, leading to the need for extra support.

One of the key risks in a project of this nature is that of the pillars deforming under stress and possibly collapsing. During this project, MDT SMART Cables and SMART Contractometers were extensively used for deformation monitoring relating to the pillars, enhancing safety and contributing significantly to the success of the project.