Influence of Joint Fissure upon the Blasting Effect of Mediunm-length Hole in Dahongshan Copper Mine

On the basis of actuality of upward fan -shaped medium-length hole blasting in Dahongshan Mine, influence of joint fissure upon the medium-upward hole blasting effect is analysed, some ameliorations about blasting parameter combined with the scene practice are made, practice shows that the blasting effect is improved after parameter optimization, the big block ratio is decreased, and the production capacity of mining field is improved.