Tunnel and Underground SpaceISSN:1225-1275(Print) 2287-1748(Online)한국암반공학회

It is necessary to increase the blasting efficiency in order to minimize the economic loss caused when the excavation cross section is reduced due to the stability problem of underground mining development, and for this, a new blasting design is proposed. In this study, the blasting efficiency of the general design in the field, the suggestion designⅠ, which added two columns to production blasting, and the suggestion design II, which added one column to create asymmetry, is compared. Advance rate and fragmentation were selected as the evaluation index of the blasting efficiency. In the case of advance rate, compared to the normal, the suggestionⅠ improved by 6.07% and the suggestionⅡ improved by 4.65%. In the case of fragmentation, based on P80, compared to the normal, the suggestionⅠ reduced about 58% and the suggestionⅡ was about 47%. Accoording to the evaluation index, the suggestion designⅠ shows better blasting efficiency than the suggestion designⅡ. But considering the additional work time and cost required for the suggestion designⅠ due to the insignificant difference in the evaluation index results, the asymmetry V-cut, the suggestion designⅡ, is judged to be a more suitable blasting design for the site.