Caving Prediction

Itasca Consulting Group, Inc. and ASC (Applied Seismology Consultants) are in an ongoing partnership to apply advanced numerical modeling tools and microseismic data analysis techniques to caving prediction. The work is part of the Mass Mining Technology (MMT) Project, an industrially funded project supporting fundamental research into the mechanics of caving, blasting, and flow in underground mass mining. Itasca studies rock mass strength and brittleness, using the Particle Flow Code (PFC) to create and test "Synthetic Rock Mass" samples (SRM) and subjecting these to induced stresses expected in situ. Using advanced tools for microseismic data analysis, ASC compares the predicted spatial temporal trends in fracturing within the samples directly with microseismic data obtained in the field. This represents a powerful combination of tools that can be applied to a wide range of rock mechanics problems and a potentially significant advancement past traditional, empirical methods of estimating rock mass properties.

Linking PFC to microseismic data is a technique that has been successfully employed within pioneering research projects to reproduce in situ seismicity measured in massive brittle rock (Hazzard and Young, 2004) and has been applied to the analysis of damage around underground excavations (Young et al., 2004). The current MMT research objectives are to extend the technique to the prediction of jointed rock mass behavior in three dimensions. The complete project description describes the techniques used, the results to date, and full citations for the references above.

Figure 3. Comparison of fracture orientations predicted by SRM testing and those inferred from microseismic data.