Assessment of relationships between drilling rate index and mechanical properties of rocks

This paper examines the relationships between drilling rate index (DRI) and some mechanical properties of rocks in order to evaluate the effect of strength and indexes of rock on rock drillability. For this purpose, some index properties (in situ Schmidt rebound hardness (SRH), Shore scleroscope hardness (SSH), and point load strength (PLS)) and strength properties (uniaxial compressive strength (UCS) and Brazilian tensile strength (BTS)) values of 32 sedimentary, igneous and metamorphic rock samples were determined. The relationships between DRI and both strength and indexes properties were evaluated using regression analysis and statistical methods. As a result, decreasing linear relationships were found between DRI and uniaxial compressive strength, Schmidt rebound hardness, Shore scleroscope hardness, diametral and axial point load strength. (C) 2012 Elsevier Ltd. All rights reserved.