A number of standard tests are conventionally carried out to characterise
strength properties of rock. The values of the parameters obtained are
often affected by planes of weakness or defects in rock structure. For the
purpose of mine design, the range in values or the class of the strength
(obtained from a number of tests) is generally more important than a
precise value (obtained from a single or limited number of tests). Research has been conducted to establish a relationship between an
indentation index and the strength of the intact rock material from the
Eastern Goldfields of Western Australia. The Tamrock Raise Boring Index
(RB-i) test, which is quick and easy to perform, was selected as the
indentation test. The results show that, for heterogeneous, strong to very strong rock,
there is a good correlation between the indentation index and the uniaxial
compressive strength and tensile strength.