Determination of the specific charge in Sri Lankan quarrying industry and tunnelling practice

Abstract

At present, Sri Lanka is inveslheavily on the development of the country's infrastructure., facilitating the vast demand for construction materials particularly, aggregate metals. Blast fragmentation is one of the most important aspects in open pit blasting. Blasted rock should be easily loaded and transported and the rock fragments should be adequately pre-conditioned (i.e. weakened) in order to reduce the energy requirements in down-stream processes such as, crushing and grinding. In Sri Lanka, the geological parameters of rocks vary throughout the island. Currently, there is a large number of metal quarries and mining activities operating all over the country, but the lack of optimum blasting practice and specific charge selection is a drawback to achieve the optimum benefits. In this research, an investigation on specific charge values have been carried out for the required level of fragmentation in quarrying industry and tunneling practice throughout Sri Lanka depending on geological parameters varying from region to region. Rock sample collection from various geological locations, determination of rock strength and hence, building-up a relationship between rock strength and specific charge values, experimentation of a fragmentation model have been carried out.