A Model for the Determination of Flyrock Range as a Function of Shot Conditions

摘要

Flyrock is the source of most of the injuries and property damage in a majority of blasting accidents in surface mines. A quantitative correlation between shot conditions and maximum flyrock range can be used to define a blasting area in which no personnel or equipment should be present during a shot. The approach used was to develop a model that correlates shot conditions and initial flyrock velocities and permits computation of flyrock range from ballistic trajectories. The Gurney formula for velocity of explosively propelled plates or fragments was adapted to explosively propelled flyrock from vertical rock faces or from bench tops. The modified Gurney formula was then calibrated with measured flyrock velocities from mining and explosives literature. Charts were then developed for possible field use that gives maximum flyrock range as a function of shot conditions.