2. Mining

Mining activities are the major drivers of seismicity. It is well established that there is a strong correlation between mining and seismicity. Mining activities that are influencing the seismic response include production and development blasting, extraction rates and the geometry of excavations. Data needs to be readily available and organised to facilitate their use into the seismic risk management process.

2.1 Production blasting database

2.1.1 Production blasting database – basic

When a blast, or a sequence of blasts is taken, voids are created and there is a disturbance in the local stress conditions. It is these changes in the stress conditions which could drive the violent failure of the surrounding rock mass.

Production blasts are always recorded in some form by the mining department, but keeping exact coordinates is less common. The large effort involved in assigning accurate coordinates is usually the main reason for not keeping an extensive blast database. Blast events may also be identified and tagged during seismic processing, but the calculated locations are often unreliable.

2.1.2 Production blasting database – advanced

For operations where the seismic reaction to production blasts is severe, more detail and accuracy is required in the production blast database. The exact time, location (X,Y,Z), tonnes of explosive used, the blast type (rise, slot, primary or secondary stopes, undercut, drawbell) is carefully recorded in advanced practice. Figure 4 shows an advanced database identifying type of blast. All blasting data is stored and is easily retrievable.