An approach to predict the length-to-diameter ratio of a rock core specimen for uniaxial compression tests

Tuncay E., Özcan N., Kalender A.

BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT, vol.78, no.7, pp.5467-5482, 2019 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 78 Issue: 7
  • Publication Date: 2019
  • Doi Number: 10.1007/s10064-019-01482-6
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.5467-5482
  • Keywords: Classification, Correction equation, Length-to-diameter ratio, Shape effect, Uniaxial compressive strength, STRENGTH, SIZE
  • Hacettepe University Affiliated: Yes


This study aimed to evaluate the effect of length-to-diameter ratio (L/D) of a rock core specimen on uniaxial compressive strength (UCS) and to investigate the optimum L/D range for different rock types. For this purpose, a considerable amount of rock block was compiled and a series of laboratory tests were carried out to determine some geo-mechanical properties of the rocks and the UCS values of test specimens having different L/Ds. Some assessments were made on the limit L/Ds [(L/D)(lim)] based on theoretically calculated values and those experimentally observed, and then some easily determined properties of the studied rocks were statistically evaluated to predict (L/D)(lim) values. By considering the results of these evaluations, some L/D classes were suggested for selection of the L/D intervals of rock specimens before uniaxial compression tests. In addition, an equation was proposed to correct the UCS values obtained from core specimens shorter than lower limits of the suggested L/D classes.