STUDY THE INFLUENCE OF THE CHOICE OF BLASTING ZONES ON THE ROCK FRAGMENTATION QUALITY AND THE STABILITY OF BENCHES IN OPEN-PIT MINING BY NUMERICAL MODELING

Abstract

In this research, the study site is a limestone quarry Ain El-Kebira located in the wilaya of Setif (Northwest -Algeria) producing limestone for cement manufacturing. The present work represents a study to measure the granulometric distribution of the blasted rock using the digital image processing software WipFrag and empirical model KuzRam, in order to evaluate the efficiency of the blasting operation and ensure the stability of the benches. In this work, we will simulate the method of exploitation while analyzing the effect of exploitation (digging trenches cutting by explosive) on the stability of the northern flank of Ain El-Kebira quarry. The calculation was carried out by phases (excavation sequence taking into account the phase before the exploitation) in different areas of the steps (5 blasts) in order to target the dangerous working platforms. It can be seen as a conclusion that the measurement of rock size by both empirical and numerical methods (KuzRam and WipFrag) gave almost similar results with accuracy of WipFrag. The change of some parameters of the blasting plan having an important influence on the blasting area, the use of large quantity of explosive negatively influenced the dimension of the fragmented rocks and the stability of the quarry edge, the use of stability software targeted the dangerous zones of the blasting (in our case software phase2 gave ideal results), these results helped the engineer for better design of the blasting plan.