Incorporating the Geological Strength Index (GSI) of the transmission strata into the attenuation law of ground vibration from open pit bench blasting operations: An investigative approach

Abstract

An effective method of quantifying the levels of ground vibration is in terms of peak particle velocity through predictive modelling using empirical formulations and analysis. Of the existing particle velocity attenuation laws, the scaled-distance concept has been widely used for estimating peak particle velocities at known distances for different explosive charge weights. Several blast design parameters have been known to influence the particle velocities. However, it is seldom that the geological characteristics of the transmission strata between the point of detonation and the monitoring point are incorporated into the attenuation laws. Consequently, this study incorporated Geological Strength Index (GSI) as the parameter representing the geological settings of the transmission strata into the particle velocity attenuation law and thereby proposed a new predictive model for blast-induced ground vibration based on the geological observations at the blasting benches and along the direction of seismic monitoring. In this process, the United States Bureau of Mines (USBM) model was modified with an addition parameter of GSI (R2=0.77). Lastly, the proposed model was validated against unused blast monitoring data (R2=0.89). Thus, this study successfully incorporated a geological parameter and modified a universal predictor for better efficiency and applicability as per the dominant geological strata characteristics.