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1 CSIR Division of Mining Technology, P.O. Box 91230, Auckland Park 2006, South Africa
2 Department of Civil Engineering, K.U. Leuven, Kasteelpark Arenberg 40, B-3001 Heverlee, Belgium andre.vervoort{at}bwk.kuleuven.ac.be
3 Department of Electrical Engineering, K.U. Leuven, Kasteelpark Arenberg 10, B-3001 Heverlee, Belgium
A series of experiments on cubic blocks of quartzite were performed to create fractures with three-dimensional characteristics so that they could serve as verification examples for numerical models that are being developed to analyse the fracture processes around mining excavations. The experiments proved to be very successful for creating 3D fracture patterns that have characteristics similar to those observed underground. The shape and position of the fracture surface is determined by the mining geometry and by the interaction with pre-existing discontinuities. However, variations of the fracture planes within the sample could not be determined from the visual study of the block surfaces. The application of a state-of-the-art medical X-ray computed tomography scanner and the development of automatic surface reconstruction software provided a method of producing a full three-dimensional, digital view of fractures within laboratory test samples. Software was developed to provide an interactive graphical method for studying the scans in three orthogonal planes simultaneously. By contouring below a selected density threshold, three-dimensional images of the fracture surfaces were produced. X-ray computed tomography was found to provide a unique means of visualizing the fractures within rock test samples, which can greatly assist the study of rock fracture processes.
