| Summary: | The measurement while drilling (MWD) technique has been used to give solutions to the charging procedure in sub-level caving mining operations with the goal of assessing geotechnical issues in the holes before charging. A geotechnical rock condition block model has been developed to improve the work done by Ghoshet al.(2018). For that, external influences in the MWD parameters are minimised and a quantitative assessment and automatic recognition of rock trendsis carried out. The analysis also assesses blasthole collapses by comparing different geotechnical rock condition situations in the blasthole with the charging length of 102 production fan-holes. This results in a model that assigns three risk levels of collapse and predicts collapses in the first half of the fan-holes for the high risk, collapses in the second half of the fan-hole for the medium risk and no collapses along the hole for the non-risk holes. The two models have been applied in full scale for one orebody in the Malmberget mine, Sweden, which comprises 10 drifts and 2500 fan shape longholes.
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