Bulletin of Engineering Geology and the Environment

, Volume 78, Issue 7, pp 5467–5482 | Cite as

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

  • Ergün TuncayEmail author
  • Nazlı Tunar Özcan
  • Aycan Kalender
Original Paper


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.


Classification Correction equation Length-to-diameter ratio Shape effect Uniaxial compressive strength 



This research was conducted by the financial support of The Scientific and Technical Research Council of Turkey (TUBITAK) with a project number of 109Y307.


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Department of Geological EngineeringHacettepe UniversityAnkaraTurkey

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