Stress field mapping using seismic stress inversion

Project overview

Faults have been shown to affect the stress field in their vicinity, which can have a significant effect on the stability of nearby mining excavations, and also on the stability of other faults in the local network. Traditional methods of determining stresses, using overcoring of strain cells, provides limited point-measurement of stresses and there are indications that the method does not work below depths of approximately 2 km. Inversion of mining-induced seismic data offers the possibility to map the flow of the stress field in volumes that are seismically active i.e. close to mining excavations and faults. The resulting stress field map will be valuable for mine design purposes (numerical stress analysis model calibration) and in understanding fault stability. The objective of this research project is to investigate the various aspects of stress inversion used in the crustal seismology field, and adapt them for use in a mining environment. This involves assessing various methods of analysis, and developing methodologies for discretizing the induced seismic event catalogue in both time and space to carry out the inversion process. The project is funded by Glencore and an NSERC Collaborative Research and Development grant.