Assessing and controlling of bench blasting-induced vibrations to minimize impacts to a neighboring community.

Abstract

Blasting is an important operation in mining production but is a source of concern due to its associated environmental impact; in particular, blasting-induced vibrations may cause structural damage and human discomfort. For decades, communities near open-pit mines have complained of blasting-induced vibrations. This study presents a methodology to predict, assess, and control ground vibrations in large open-pit mines operating close to a community. To conduct this study, 178 levels of blastinginduced vibrations were recorded in an area encompassing a large open-pit iron ore mine and a neighboring community located in the Quadril atero Ferrífero, state of Minas Gerais, Brazil. Collected data were processed with multiple regression techniques to obtain the blasting vibration attenuation law to predict the levels of blasting-induced vibrations for the locality studied with knowledge of only the maximum explosive charge per delay and the distance to the blasting point. Brazilian and international admissibility standards of blasting-induced vibration, the minimum distance between the mine and community and the constants obtained from the regression were used to establish the maximum explosive charge per delay for an acceptable ground vibration level that would not cause structural damage and human discomfort. Finally, the proposed methodology was validated by comparing the predicted ground vibrations levels to measured values. The results demonstrate that this methodology can be applied to any open-pit mine to control blasting-induced vibration effects.