Abstract
Many studies have been conducted on the size effects behavior of intact rocks and the majority of them have focused on a standard ratio of length to diameter (slenderness ratio) as determined by the International Society for Rock Mechanics (ISRM). The main aim of this research was to investigate the correlation between slenderness ratio and the mechanical properties of Gosford sandstone over a much broader range of slenderness ratios. The data showed that there was a general descending trend for the uniaxial compressive strength (UCS) as slenderness ratio increased. Similarly, Young’s Modulus displayed a descending trend with increasing slenderness ratio. No discernible correlation could be established between Poisson’s ratio and slenderness ratio. Also, it was revealed that single shearing and vertical splitting were the dominant failure modes for Gosford sandstone samples with different diameter and slenderness ratio.