Break blasting parameters for driving a roadway in rock with high residual stress

The formation of a normal blasting crater for the break blasting of a roadway in rock with high residual stress was investigated based on the theory of cylindrical blasting crater. The criterion on the formation of a normal blasting crater, and the parameters of stoping blasting for driving a roadway in rock with high residual stress as well, were deduced. It is concluded from investigation that the parameters of break blasting need to be modified due to the effect of residual stress, and that the higher the residual stress is, the smaller the burden and the blasthole separation are, the larger the specific charge and the number of round blastholes are. Finally, it is pointed out that high explosive can be used to decrease the rate at which the parameters of break blasting for driving a roadway change due to the effect of high residual stress.