Landslide detection of gold mines tailing dams
Remote monitoring with SENSECOM-AC series
There are many examples of cascade dam failures in gold mines. These have resulted in the release of toxic mine waste into the surrounding area or the disastrous consequences of flooding villages and towns below the dams. The early detection of landslides on tailings dams is critical.
As was done in the past
Until recently, one effective method used to shift the soil on a gold mine dam in South Africa was one in which poles were driven into the ground on either side of the access road below the dam and the distance between them was monitored daily with a tape measure. In this way, a number of pairs of poles were placed along each cascade dam. Daily manual monitoring was labor, time, and record keeping intensive. Measurement accuracy was limited and soil movement may not have been detected in a timely manner; measurements were limited to the lower portion of the dam. The risk of not detecting the breached dam and its breaching was still high.
As it stands today
Today, these gold mines use SENSECOM-ACH tiltmeters, which are attached to rods embedded in the soil, positioned at different levels in the alluvial dam area, to detect landslides on the dams of the cascade tailings ponds. An eventual landslide will cause a change in the tilt of the rod. Even with a minimal change in angle of 1°, the device detects the change in tilt and sends an alarm immediately. The device is energy-efficient, so even with a small battery it can run for several years without its replacement.
At the gold mines in South Africa, at a relatively low investment cost, they have a solution that not only saves significant operating costs, but more importantly, allows them to detect one of the potential key signs of a dam breach more reliably and much earlier than before. This will enable early action to be taken against a breach or rupture of the dam, which would otherwise result in the release of toxic substances or catastrophic flooding of the area below the dam.
Use of the equipment in other areas
SENSECOM-AC series devices are used in many other areas, e.g. detection of changes in the inclination of high voltage pylons, high-rise buildings and structures, rock bodies, etc. Devices of a similar nature SENSECOM-NFQ are used to detect the frequency of natural vibrations of structures, typically bridges, where their change indicates a disturbance in their stiffness.