Investigations into the influence of decking on rock fragmentation and ground vibrations by blasting in shallow benches of limestone quarries – a case study

Abstract

In any quarry blasting, rock breakage is considered to be one of the significant components for carrying out the ground preparation to achieve higher production rate and also to sustain productivity. However, the performance of the blasting in terms of controlling environmental effects and the costs involved in the operation determine the profitability and sustainability of the mining company to huge extent. Thus it is necessary to study the existing conditions and accordingly implement the cost-effective technique which may enhance the blast performance with minimizing the environmental effects. Here, the decking practice in the blastholes is one of such costeffective techniques, which is being considered to improve the blast results in the form of improvised fragmentation, effective throw, reduced vibration and less back break. Therefore, a case study involving the deep hole blasts carried out with conventional decking practice in the shallow benches of a limestone quarry located in the state of Tamil Nadu. Using the image analysis software - Fragalyst 4.0, the images of blasted muckpile were then analyzed to determine the mean fragment size and the size distribution of the fragments. It was observed that the deck blasting technique is found to be economical and also reduces the ground vibration considerably. This paper discusses the decking practices that are developed and subsequently implemented in the quarry blasting and finally outlines the recommendations to be taken for improving the performance of blasts in shallow benches of the quarry.