Environmental safety during explosion of pressure charges

Explosive crushing of over-sized blocks always creates environmental stress. The article presents the assessment of the air-blast during the explosion of pressure charges. We have calculated the air-blast parameters during the explosion of open charges with the parameters close to the used in slap-dab at ballast quarries, and assessed the impact of various factors on the air-blast formed during the crushing of over-sized blocks. Comparison of the value of overpressure at the shock front with the value of permissible exposure level shows that the use of short-delayed blasting does not always ensure the safety of the explosion in terms of the air-blast. It is established that the minimum value corresponds to the direction along the row of charges against propagation axis of detonation and is achieved with separate airblast arrival from each group of charges.