Application of ground penetrating radar to identify the locations of sub-surface anomalies at Kansanshi Mine, Zambia

Authors: Smith, NK Download Paper

DOI https://doi.org/10.36487/ACG_rep/1308_56_Smith

Cite As:
Smith, NK 2013, 'Application of ground penetrating radar to identify the locations of sub-surface anomalies at Kansanshi Mine, Zambia', in PM Dight (ed.), Slope Stability 2013: Proceedings of the 2013 International Symposium on Slope Stability in Open Pit Mining and Civil Engineering, Australian Centre for Geomechanics, Perth, pp. 815-828, https://doi.org/10.36487/ACG_rep/1308_56_Smith



Abstract:
Geotechnical zones within the North West Pit and Main Pit of Kansanshi Mine consist of a regolith profile with isolated marble blocks, referred to as ‘boulders’ within a highly weathered, unmineralised saprolite. The majority of the regolith is free-dig area with pre-split blasting to target boulders and create a smooth face. A serious rockfall risk is associated with irregularly-shaped boulders protruding from the batter face if not effectively treated during pre-splitting. Due to the random distribution of boulders within the regolith profile, drilling used a closely spaced pattern, with a large number of rigs, and this proved to be very costly. A ground probing radar system utilising a 50 MHz, unshielded, Rough Terrain Antenna (RTA) to scan a predetermined grid over a planned blast pattern, is able to detect subsurface anomalies such as boulders and cavities. Scan data can be imported into Surpac™ and manipulated to create a three dimensional boulder model from which an effective blast pattern could be designed. Results have indicated several significant benefits; up to 80% cost saving in terms of drill and blast, more effective utilisation of drilling resources in hard rock areas, effective presplitting of boulders on highwall faces reducing rockfall risk and reduced equipment damage through identification of subsurface cavities.

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