Pfitzner, MJ, Westman, E, Morgan, M, Finn, D & Beck, DA 2010, 'Estimation of rock mass changes induced by hydraulic fracturing and cave mining by double difference passive tomography', in Y Potvin (ed.), Caving 2010: Proceedings of the Second International Symposium on Block and Sublevel Caving, Australian Centre for Geomechanics, Perth, pp. 677-684, https://doi.org/10.36487/ACG_rep/1002_47_Pfitzner
(https://papers.acg.uwa.edu.au/p/1002_47_Pfitzner/)
Abstract: Double difference (DD) passive seismic tomography was employed at the Ridgeway Deeps block cave project to identify the magnitude and extent of preconditioning due to hydraulic fracturing and to identify zones of damage and increased stress during the undercutting and early stages of caving. This was done by identifying zones of decreased seismic velocity over the period corresponding to the preconditioning project and cave initiation. The data obtained was used in parallel with numerical model calibration studies to improve understanding of the relationship between velocity changes, stress and damage and also to quantify the effectiveness of a preconditioning campaign.

The approach was able to quantify the induced changes successfully, but there were a number of learning points for future projects. The technique is seen as an important analysis tool that can be used to leverage significant additional value from existing seismic systems and data sets.