Estimation of Mode i Fracture Toughness of Rock by Semi-Circular Bend Test under Confining Pressure Condition

Minami Kataoka, Eqlima Mahdavi, Takahiro Funatsu, Takashi Takehara, Yuzo Obara, Katsunori Fukui, Kimihiro Hashiba

    Research output: Contribution to journalConference articlepeer-review

    9 Citations (Scopus)

    Abstract

    It is essential to understand the mode I fracture toughness of rock under in situ conditions found underground, such as confining pressure, for assessment of the stability of underground rock structures. Some researchers have performed several types of fracture toughness tests of rocks under confining pressure condition. However, the ordinary fracture toughness tests do not consider the effect of confining pressure in their estimation equations. A modified estimation equation for the mode I fracture toughness of rock under confining pressure condition was suggested in this study. This study was intended for the semi-circular bend (SCB) test, which is one of the ISRM-suggested methods for determining the mode I fracture toughness of rock. The SCB test under various confining pressures from 0 to 10 MPa was performed using Kimachi sandstone. A finite element analysis of the SCB test considering several confining pressure conditions was performed to calculate the stress intensity factor. Based on the numerical simulation results, the modification of the fracture toughness estimation was suggested. Applicability of the suggested estimation was discussed with comparing the mode I fracture toughness of the rock obtained in this study and previous research.

    Original languageEnglish
    Pages (from-to)886-893
    Number of pages8
    JournalProcedia Engineering
    Volume191
    DOIs
    Publication statusPublished - Jan 1 2017
    EventISRM European Rock Mechanics Symposium, EUROCK 2017 - Ostrava, Czech Republic
    Duration: Jun 20 2017Jun 22 2017

    All Science Journal Classification (ASJC) codes

    • Engineering(all)

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