Geotechnical design considerations for Dugald River — from slot to sequence

Rhett de Vries, Rhett Hassell, John Player
2015 Proceedings of the International Seminar on Design Methods in Underground Mining   unpublished
Concerns regarding the uncertainty of stope dilution at the MMG Limited's Dugald River underground mine led to a trial stoping program to acquire full-scale comprehensive geotechnical information and to test the validity of the geotechnical and mining parameters. A total of 19 stopes were mined by sublevel open stoping with cemented rockfill (CRF). Specific studies were completed on the rock mass response to mining, rock stress and property measurements, stope blast vibration monitoring,
more » ... monitoring, production drilling deviation, CRF optimisation, re-logging of diamond core for structural and geotechnical information. Based on the trial stoping results, key geotechnical inputs into mine design and scheduling were provided. These included:  Stope drill and blast parameters such as borehole orientation, explosive type and stope boundary stand-off distances.  Oredrive and crosscut drive locations to achieve required stope drilling parameters.  Stope strike length and overbreak predictions.  CRF optimisation.  Development through CRF.  The location and sizing of capital development in relation to orebody and major lithological units.  Ground support standards based on expected damage from stress.  Stope sequencing to minimise stress concentrations and location of regional pillars. The considerable volume of data and the practical experience gained during the trial mining greatly increased the geotechnical knowledge of the rock mass and its response to mining. This allowed for a wide range of geotechnical design considerations to be applied to the project feasibility study at a higher confidence level.
doi:10.36487/acg_rep/1511_07_de_vries fatcat:wxgrltmjifat5m2u7f3qo6o7d4