INVESTIGATING THE RELATIONSHIP BETWEEN THE BRITTLENESS INDEX AND CRACK INITIATION STRESS FOR THE GRANITE UNDER TRIAXIAL COMPRESSION

XUN XI; QIFENG GUO; YING ZHANG; JILIANG PAN; MEIFENG CAI

doi:10.1590/1679-78255984

INVESTIGATING THE RELATIONSHIP BETWEEN THE BRITTLENESS INDEX AND CRACK INITIATION STRESS FOR THE GRANITE UNDER TRIAXIAL COMPRESSION

Authors

XUN XI SCHOOL OF CIVIL AND RESOURCE ENGINEERING, UNIVERSITY OF SCIENCE AND TECHNOLOGY BEIJING, BEIJING, 100083, CHINA. / DEPARTMENT OF CIVIL AND ENVIRONMENTAL ENGINEERING, UNIVERSITY OF STRATHCLYDE, GLASGOW, G1 1XJ, UK HTTPS://ORCID.ORG/0000-0002-8667-1950
QIFENG GUO SCHOOL OF CIVIL AND RESOURCE ENGINEERING, UNIVERSITY OF SCIENCE AND TECHNOLOGY BEIJING, BEIJING, 100083, CHINA HTTP://ORCID.ORG/0000-0003-0904-7342
YING ZHANG SCHOOL OF CIVIL AND RESOURCE ENGINEERING, UNIVERSITY OF SCIENCE AND TECHNOLOGY BEIJING, BEIJING, 100083, CHINA HTTP://ORCID.ORG/0000-0003-1977-7736
JILIANG PAN SCHOOL OF CIVIL AND RESOURCE ENGINEERING, UNIVERSITY OF SCIENCE AND TECHNOLOGY BEIJING, BEIJING, 100083, CHINA HTTP://ORCID.ORG/0000-0001-5948-2081
MEIFENG CAI SCHOOL OF CIVIL AND RESOURCE ENGINEERING, UNIVERSITY OF SCIENCE AND TECHNOLOGY BEIJING, BEIJING, 100083, CHINA HTTP://ORCID.ORG/0000-0002-8582-5698

DOI:

https://doi.org/10.1590/1679-78255984

Abstract

THE BRITTLE FAILURE OF ROCK IS CLOSELY RELATED TO THE ROCK CRACK INITIATION, PROPAGATION, COALESCENCES AND NUCLEATION. ALTHOUGH MANY BRITTLENESS INDEXES HAVE BEEN PROPOSED TO DESCRIBE THE BRITTLE BEHAVIOR OF ROCKS, THE RELATIONSHIP BETWEEN THE BRITTLENESS INDEX AND CRACK INITIATION STRESS UNDER TRIAXIAL COMPRESSIVE STATES HAS NOT BEEN FULLY UNDERSTOOD. THIS PAPER INTRODUCED THE CURRENT MAIN BRITTLENESS INDEXES AND DISCUSSED THEIR APPLICABILITIES FOR TRIAXIAL COMPRESSIVE TESTS. GRANITE SPECIMENS FROM A GOLD MINE ARE PREPARED FOR EXPERIMENTAL TESTS. THE TRIAXIAL COMPRESSIVE TESTS ARE CARRIED OUT ON STIFF TESTING MACHINE AND THE CONFINING PRESSURES ARE 5 TO 110 MPA. EXPERIMENTAL RESULTS ON THE STRESS-STRAIN CURVES SHOW THAT THE POST-PEAK BEHAVIORS OF THE GRANITE UNDER CONFINING PRESSURES ARE IN CLASS I AND CLASS II TYPES. THE BRITTLENESS INDEXES, CRACK INITIATION STRESS, COMPRESSIVE STRENGTH, ELASTIC MODULS AND POISSON’S RATIO OF THE GRANITE ARE OBTAINED AND DISCUSSED. IT HAS BEEN FOUND THAT, THE CRACK INITIATION STRESS LINEARLY INCREASES WITH THE INCREASING OF CONFINING PRESSURE. MOREOVER, A POWER FUNCTION CAN DESCRIBE THE RELATIONSHIP BETWEEN THE BRITTLENESS INDEX AND CRACK INITIATION STRESS FOR CLASS I ROCK BEHAVIOR WHILE AN EXPONENTIAL FUNCTION CAN DESCRIBE THE RELATIONSHIP BETWEEN THE BRITTLENESS INDEX AND CRACK INITIATION STRESS FOR CLASS II ROCK BEHAVIOR.

Downloads

Published

2020-09-22

Issue

Vol. 17 No. 8 (2020)

Section

Articles

License

Authors who publish with this journal agree to the following terms:

Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License [CC BY] that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).