Diagnostics of Production Blasts in a Deep Underground Mine

摘要

An extensive blast monitoring program has been carried out to study explosiveperformance and the effectiveness of blast designs in production blasts in a deepunderground mine. Comprehensive monitoring of blasting vibrations through multi-stationhigh-capacity high-frequency accelerometers, and borehole deformation history have beenthe main tools of such analysis. The mining activity involves relatively unstressed stopesas well as highly stressed stopes. More than 30 production blasts have been monitored,and the respective vibrations from close-range as well as distant seismic stations havebeen analyzed, and the vibration parameters (amplitude and frequency) have beencorrelated with explosive charge weight in the holes. It is found that the correlationbetween blasting rounds and the corresponding vibration amplitudes often have poorcorrelation for a very significant portion of the blasts. These point to either explosivecharge malfunction in those specific blast holes, or inadequate blast design, or the effect ofhigh in-situ stresses, or any combination thereof. This paper analyzes these variables andtheir effect on the overall blasting operation at the mine.