ISRM-suggested method for determining the mode i static fracture toughness using semi-circular bend specimen

M. D. Kuruppu, Y. Obara, M. R. Ayatollahi, K. P. Chong, T. Funatsu

    Research output: Contribution to journalArticlepeer-review

    317 Citations (Scopus)


    The International Society for Rock Mechanics has so far developed two standard methods for the determination of static fracture toughness of rock. They used three different core-based specimens and tests were to be performed on a typical laboratory compression or tension load frame. Another method to determine the mode I fracture toughness of rock using semi-circular bend specimen is herein presented. The specimen is semi-circular in shape and made from typical cores taken from the rock with any relative material directions noted. The specimens are tested in three-point bending using a laboratory compression test instrument. The failure load along with its dimensions is used to determine the fracture toughness. Most sedimentary rocks which are layered in structure may exhibit fracture properties that depend on the orientation and therefore measurements in more than one material direction may be necessary. The fracture toughness measurements are expected to yield a size-independent material property if certain minimum specimen size requirements are satisfied.

    Original languageEnglish
    Pages (from-to)267-274
    Number of pages8
    JournalRock Mechanics and Rock Engineering
    Issue number1
    Publication statusPublished - Jan 2014

    All Science Journal Classification (ASJC) codes

    • Civil and Structural Engineering
    • Geotechnical Engineering and Engineering Geology
    • Geology


    Dive into the research topics of 'ISRM-suggested method for determining the mode i static fracture toughness using semi-circular bend specimen'. Together they form a unique fingerprint.

    Cite this