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Studying the effect of non‐spherical micro‐particles on Hoek–Brown strength parameter m i using numerical true triaxial compressive tests
Author(s) -
Zhang Qi,
Zhu HeHua,
Zhang Lianyang
Publication year - 2015
Publication title -
international journal for numerical and analytical methods in geomechanics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.419
H-Index - 91
eISSN - 1096-9853
pISSN - 0363-9061
DOI - 10.1002/nag.2310
Subject(s) - compressive strength , particle flow , particle (ecology) , geotechnical engineering , particle size , hoek–brown failure criterion , mechanics , materials science , flow (mathematics) , discrete element method , composite material , physics , geology , rock mass classification , paleontology , oceanography
SUMMARY The strength parameter m i in the Hoek–Brown strength criterion is empirical and was developed by trial and error. To better understand the fundamental relationship between m i and the physical characteristics of intact rock, this paper presents a systematic study of m i by representing intact rock as a densely packed cemented particle material and simulating its mechanical behavior using particle flow modeling. Specifically, the three‐dimensional particle flow code (PFC3D) was used to conduct numerical true triaxial compression tests on intact rock and to investigate the effect of non‐spherical micro‐particle parameters on m i . To generate numerical intact rock specimens containing non‐spherical micro‐particles, a new genesis process was proposed, and a specific loop algorithm was used based on the efficiency of the process and the acceptability of generated specimens. Four main parameters—number, aspect ratio, size, and shape—of non‐spherical micro‐particles were studied, and the results indicated that they all have great effect on m i . The strength parameter m i increases when the number, aspect ratio, or size is larger or the shape becomes more irregular, mainly as a result of the higher level of interlocking between particles. This confirms the observations from engineering experience and laboratory experiments. To simulate the right strength parameter m i , it is important to use appropriate non‐spherical micro‐particles by controlling these four parameters. This is further demonstrated by the simulation of two widely studied rocks, Lac du Bonnet granite and Carrara marble. Copyright © 2014 John Wiley & Sons, Ltd.