Ground Vibrations and Air Blast Effects Induced by Blasting in Open Pit Mines: Case of Metlaoui Mining Basin, Southwestern Tunisia

Abstract

Blasting is widely used in quarries and mining production processes. It is the beneficial industrial technology which provides achievement of expected results in a short period of time with relatively low cost. Never one less, blasts produce undesirable vibrations and sounds. This current investigation reports the ground motion and airblast over pressure measurements around the open pit mine nearby Metlaoui village (south-western Tunisia). An empirical relation proposed by USBM was utilized to calculate K (site constant) and n (slope of the PPV vs scaled distance) and verifies whether the recorded shots overcame the thresholds indicated by DIN and USBM. The site parameters obtained provide us with the propagation equation of the blast induced seismic waves in the study site. Also, an overview of frequency for the study area revealed the dominance of low frequencies (>40 Hz). Such values can cause damage to the nearby structures when a specific PPV value is reached by blasting. Moreover, it has been demonstrated in this study that all over pressure magnitudes are less than 134 dB, which is the safe limit of air blast level.