Engineers Australia

The applicability of index tests on weathered rock: Interrelationships and experience from The Pilbara, Western Australia

Ben Follett, Tony Gourlay, Amos Ngoi and Gavin Wearne


Index tests can provide useful correlations with the mechanical properties of rock, but must be used with caution in lower strength and weathered materials. The authors summarize the results from laboratory testing and visual examination of rock from 1300m of core taken from 69 nearshore boreholes on the coast of the Pilbara in Western Australia. Interrelationships between weathering and index properties are discussed; correlations between the parameters are proposed and the limitations of index tests are considered.