Application Of Tomography And Dynamic Parameter Analysis In A Block Caving Mine

We use seismic passive tomography and micro-seismic clustering techniques (Dynamic Parameter Analysis — DPA) as interpretive tools to understand the continual time and spatial evolution of local stresses in a block caving mine. We perform weekly analysis using a rich micro-seismic dataset recorded with a local system. In DPA we combine the collective behavior of many micro-seismic events that occur in the same rock volume, to describe the temporal-spatial deformation of the rockmass and identify dynamic stress changes. In Tomography we use micro-seismic event travel time information to resolve subtle variations in the velocity structure which can be related to stress changes and rock damage. Combining the information from the two methods allows for a more robust interpretation of the results. We illustrate the applicability of the two methods by showing an example of stress loading on a lateral cave wall during cave development and subsequent de-stressing. This information is extremely useful in the control of the block cave development, the geometry of the associated surface subsidence, and for block caving managing operations including load support, blast sequencing to redistribute concentrated loads (high stress regions).