ABSTRACT
The Uniaxial Compressive Strength (UCS) test results carried out for intact rocks under laboratory condition are used widely in rock mechanics analyses. However, if the rock engineers performs UCS testing program to evaluate the impact of shape and size on rock materials, unfortunately, they can encounter with some surprising results, particularly for special materials like coal and rock salt. In addition, the grain size (d) is effective on UCS test results. In this study, the change in UCS attributable to scale was determined for Kars-Kagızman rock salt, and the results are presented to emphasize the importance of the scale effect on failure phenomena in rock salt under uniaxial compression. With statistical analysis, the critical Height/Diameter (H/D) and Height/Width (H/W) ratios were determined to be 2.0 for core specimens and 2.0 for prismatic specimens.
