In this paper is presented studies whose main objective was to verify if the high dispersion of particle velocity values gotten during ground vibration monitoring of rock blasting in a mine located in the Municipality of Limeira, State of São Paulo, were related to the firing time variations in the nonelectric MS delay detonators, in relation to the nominal ones. The experiments were carried out in January and June 2004 and the adopted method to estimate the firing time of these detonators produced results that indicate consistence, but there is still a need for more detailed studies. The results of this study indicate the necessity to consider these variations when elaborating blasting designs, so that environmental impacts, such as safety and economical aspects, are attended to.
Vibration; MS delay; detonations
