Using pre-splitting controlled blasting method and comparing it with non-control method in Chehel Kooreh copper mine

In blasting operations in tunnels, the occurrence of back break caused by the high energy content of explosives leads to many problems. In this project, it is tried to solve the problems caused by non-controlling blasting by controlled blasting in a pre-splitting method in one of the march tunnels of the chehel Kooreh mine in Zahedan. In order to design the blasting pattern in the tunnel section, the "theory of energy transfer" and "nitronobel (Swedish) methods" were investigated with parallel and angular holes, which ultimately led to a blast pattern based on the "energy transfer theory" with parallel holes as the final design of the selection And the control hole pattern was also designed in a "pre-splitting" manner. Finally, the proposed design was implemented in the march tunnel of the Chehel kooreh mine. Finding the results of the blasting on the basis of the proposed design showed that the face and the roof and walls were much more smooth than the blasting based operation according to the current design, which would result in more and better matching of the units with the walls and roof And preventing increased stress concentration on them. To evaluate the pre-splitting controlled blasting performance, the QCB factor is used quantitatively, after which the factor was used, the controlled blasting performance of the Chehel kooreh mine march tunnel was excellent based on the proposed design.