Estimation of penetration rate in percussive drilling by means of coarseness index and mean particle size

The relationships between the coarseness index (CI), mean particle size, and specific surface area (SSA) determined at the laboratory and penetration rate determined at a limestone quarry have been investigated. The coarseness index, specific surface area and mean particle size were calculated from the data of sieve analysis for each of the nineteen blastholes undertaken for study. The penetration rates were correlated with the coarseness index, the mean particle size and the specific surface area by using least square regression method. It was found that an inverse exponential relation between penetration rate and specific surface area exists.