The challenge
Slope instability and weak seismic events
One of the key requirements in open-cut mining is assessment of slope stability.
Microseismic techniques have been used for monitoring and interpreting rock-fracturing events that may lead to pit-wall collapse.
A challenge for microseismics is that many seismic events associated with unstable activities are weak and not picked up by conventional microseismic monitoring methods.
In a partially confined strata environment – such as near open-pit slopes and underground tunnels – the stress needed to break the partially confined rock mass may not be high, leading to many weak microseismic events.
Many of these weak events may challenge the integrity of the rock mass, but their energy weakness means they hardly trigger more than three geophone (a device that measures ground movement) stations, so are often not recorded in conventional microseismic monitoring.
Yet, as these weak events contain information of strata instability, we believe it’s important for them to be recorded and interpreted to further improve the safety of mining operations.
Our response
Measuring micorseimsmic events
Our Microseismic Research Team has developed a novel approach to monitor weak microseismicity using smart algorithms to automatically detect and interpret these weak seismic signals.
The weak seismic event detection and interpretation are achieved using continuous data recording and intelligent seismic event discrimination algorithms.
Event location can be obtained using one or more geophone stations.
The seismic signals may be weak but can add a further dimension enhancing mine safety and improving risk.
The results
Making (microseismic) waves in pit wall safety
Our technique has been successfully tested in two open-cut mines with more trials at underground mines for roadway stability in progress.
These initial trials have provided reliable monitoring results alowing pit operators to improve mining risk management.
Future work is aiming to develop a reliable system to record and interpret these weak seismic events in real-time, improving efficiency and safety for open-cut and underground mines.
Two final project reports have been accepted by our academic partners and industry clients. One journal paper and one conference paper have been published.