Investigation of the effect of physico-mechanical properties of rocks on drillability

In this study, drilling speeds were measured in situ by keeping the drill bit and machine working parameters (impact, pressure, air pressure and rotation) constant during drilling-blasting operations on six different open mines (4 limestones, 1 clay and 1 feldspar quarries). From these quarries, shapeless blocks samples and rock chipping specimens from blasting holes were taken for laboratory experiments. The physical and mechanical properties of the rocks from the block samples and coarseness index from chip samples were determined. Sievers miniature drilling tests and brittleness tests were also performed to determine the drilling rate index (DRI) values of the rocks. As a result, the results of the laboratory tests and insitu drilling data were evaluated statistically. Significant relationships were found between the physical and mechanical properties of the rock and the measured drilling speed. It has been determined that the drillability values determined in the laboratory can be reliably used in predicting the rate of penetration in drilling-blasting operations.