Track 6: Mining Engineering and Mine Planning

Discussion and conclusions The newly developed Stress Inversion from Mine Seismicity (SIMS) method was used to infer information about the stress state at a South American mine. Compared to existing methods from crustal seismology, SIMS is able to make use of a greater portion of catalogues of mining-induced seismicity. The results of the inversion for the event clusters considered in this study were in reasonably good agreement with the mine’s currently adopted stress state in terms of orientation and ratios. It is important to mention that the measurements themselves are uncertain in terms of orientation of principal stresses, which creates a need for new and improved measurements. However, our results provide some degree of confidence in the adopted stress state in the context of tasks such as numerical modelling and assessment of tunnel loading conditions, which is critical for rockburst hazard evaluation. In light of this study, the mine is considering organizing new stress measurements to confirm our findings. The results of the study also demonstrate that it is possible to perform advanced seismic analysis (e.g. mechanism and stress inversion) with a small system (between four and ten geophones). This requires that the recorded waveforms are of high quality, which is achieved by installing sensors in grouted boreholes away from sources of mechanical and electrical noise, and away from large heterogeneities (e.g. stopes with associated yield Figure 12 Results of the stress inversion for events in cluster C, which all belong to the ‘scattered’ category.

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