Correlating seismic wave velocity measurements with mining activities at Williams Mine

摘要

Seismic wave velocities are sensitive to rock mass properties including fracture density, orientation, stress magnitude and orientation. By measuring small changes, of the order of 0.01%, in the seismic wave velocities over time, it is possible for track changes in the rock mass properties to occur. In mining, the rock mass properties are altering as the rock is removed or pillars are formed. By tracking these changes, it may be possible to get a better understanding of the effect mining has on the rock mass properties. These changing rock mass properties are important for reliable static stress modelling of the mine and for stability analysis. We use an active seismic source where a pneumatic hammer generates repeatable impacts that can be measured a few hundred metres away from the source. This allows us to measure directional velocity changes where these can be compared with mining and microseismic activity. This is the first step in understanding the effect of mining on the rock mass properties over time.