Investigating the Effect of slot on Attenuation of the blast-induced land vibration by Numerical Modeling

One of the solutions to reduce the transmission of blast-induced ground vibration may be application of open discontinuity as a barrier to the seismic wave path. In this study, the slot effect on the attenuation of blast-induced vibration by the numerical methods is investigated. Modeling the blasting environment has been done through creating a blast hole and recording particle velocity in the four different zones within close to far from blasting. Also by creating a slot and changing its depth, the effect of slot's position and depth is achieved. The effectiveness of the slot position in two states of active and passive isolation has also been investigated. The results of the study show reduction of ground vibration up to 85% by employment of slot. However, the effect of this attenuation at surface is higher than the deep position. Also the biggest change in attenuation is created in the first step of creating a slot (equal to half the length of the hole) that it is about 40% in near zones and about 10% in far zones. In this this investigation, analysis of the data sets resulted in best fitting relationship between the slot depth and attenuation with excellent determination index (R2=0.9). This study shows that the passive method in attenuation of surface vibrations is more effective than active method. However, as the slot depth increases, the effectiveness of both methods gets close together.