Background

Rock falls, cave-ins and collapses are very real risks in an underground mine. These disastrous events can lead to serious injury or even death, cause damage or loss of mine equipment and facilities, and result in substantial production delays.

One of the best ways to mitigate the risk posed by unstable ground and rock faces is to have a comprehensive geotechnical monitoring infrastructure. Ideally, this infrastructure should consist of a series of relevant geotechnical monitoring instruments that are connected to a central network. This allows data to be efficiently collected, moved to a central point, and analyzed.

Instrumentation

Geotechnical monitoring instruments commonly used for data gathering in underground mines include:

• Extensometers, to measure displacement (e.g. MDT SMART MPBX)
• Instrumented Cable Bolts, to measure displacement, strain, and load (e.g. MDT SMART Cable Bolt)
• Contractometers, to measure convergence and compression (e.g. MDT SMART Contractometer)
• Ground Movement Monitors, to measure general ground movement (single-point) (e.g. MDT SMART GMM100)
• Sloughmeters, to measure sloughing or caving (e.g. MDT Sloughmeter)

The Wireless Advantage

Due to the increasing depth and scale of many modern mines, collecting data from geotechnical instruments, especially those located in hard-to-access places or remote parts of the mine can be a challenge, especially if connecting up all these instruments to a central monitoring point involves the installation and maintenance of kilometres of wiring.

The ideal solution to this problem is for the geotechnical monitoring network to be of the wireless mesh type. In this type of arrangement, robust monitoring instruments, connected in sets of three to battery-powered wireless nodes (with a battery pack lasting up to three years), collect data and send it from node to node, over long distances if necessary, until a network gateway is reached. At that point, the data will enter the mine’s existing LAN network and be available to mine engineers for interpretation and use.

In recent times, there has been a definite shift away from cable-based networks to wireless geotechnical monitoring networks because they offer a variety of benefits. Some of the advantages of connecting your MDT instrumentation to a wireless network (e.g. those powered by Newtrax solutions and incorporation wireless nodes) are:

• Lower maintenance and installation costs – No expensive, labour-intensive cable to fit in every nook and cranny of the mine, and look after.
• Reduced energy consumption – Wireless nodes are powered by long-life batteries.
• Less downtime – No cabling to snag or break, which means less likelihood of faults.
• Longer infrastructural lifespan – Cabling tends to corrode, become brittle, and lose efficiency as it becomes older, unlike wireless networks.
• Enhanced mine safety – A more responsive, efficient, and reliable monitoring system means more control and better anticipation of and response to potentially hazardous situations.

Data that Counts

With all the instruments connected to the wireless geotechnical monitoring network, powered by Newtrax, data can be easily collected and used to continuously monitor the state of the geological environment and formations in and around the mine.

Safety limits can be predefined, and the system will provide warnings as soon as a limit is reached or exceeded, allowing mine engineers and managers to make quality decisions, manage dangerous situations, and reduce risks by taking appropriate action – thereby making sure the mine is a safer and more productive place all the time.