Investigation of the relationship between rock brittleness index and rock mechanics characteristics of rocks

Brittleness is one of the important mechanical properties of rocks. In recent years, it has become an important parameter used in performance estimation especially in the field of excavation mechanics. The brittleness, which is defined as a behaviour of rock material in rock mechanics, provides important data in understanding the issues such as excavability, abrasiveness, perforability, cuttability and usability as material. Brittleness can be found empirically by various researchers using some special test equipment and also with the help of strength properties of rocks. The purpose of this study is to compare the physical and mechanical properties of five different rocks taken from different regions of Turkey. For this purpose, the brittleness characteristics of the rocks were determined both by the experimentally developed brittleness (S20) test and by the empirical formulas (B1, B2, B3 and B4) based on the strength characteristics of the rocks commonly used in the literature. Then, the physical and mechanical properties of rocks such as uniaxial compressive strength, indirect tensile strength, point loading strength, Schmidt hammer hardness, density and dry weight loss were determined by rock mechanics tests and compared with their brittleness properties. According to the statistical evaluation, strong and significant relationships were found between S20 brittleness value with RL and Is(50) values.