Abstract
The suitability of the geotechnical bench slope design is usually contingent on "good practice wall control blasting". Actual performance of the bench slopes (walls) can vary significantly from expectations, especially during initial stages of mining while optimizing drill and blast designs. How do you determine whether the poor wall performance is because of poor blasting or challenging geotechnical conditions? This presentation provides hard-rock case study observations, a framework to audit the wall control blasting (from geotechnical perspective) and guidelines for modifying the bench design based on quality of the implementation practices.
The presentation examines design compliance tools and places a time-frame on rationalizing the suitability of the geotechnical design for ranges for blasting, excavation and scaling performance, as well as the aggravation of typical risks observed in structurally controlled deposits.
The guidelines also provide considerations for presented auditing and guidelines with respect to the pit phases. Where the open pit enters the final wall configuration, the bench design may need to be relaxed to account for known risks or uncertainties in the wall performance. Interim phases, however, may be used to trial steeper designs and benches with excessive overbreak or crest loss may be acceptable as part of experimenting with the wall control practices.