Influence of confinement dependent failure processes on rock mass strength at depth

Benoît Valley, Bo Hyun Kim, Fidelis T. Suorineni, Navid Bahrani, Rob P. Bewick, Peter K. Kaiser

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Citations (Scopus)

Abstract

Changes of failure mechanism with increasing confinement, from tensile to shear dominated failure, is widely observed in the rupture of samples in laboratory and in rock masses in situ. However, common failure criteria typically consider only shear mechanisms. A hybrid criteria based on a sigmoid function is introduced to account for a transition from tensile to shear dominated failure with increasing confinement. When evaluated by fitting to an extensive laboratory database the sigmoid criteria does not provide a better fit compared to the Hoek-Brown failure envelope, but provides insight into rock strength controlling factors that have significant consequences with respect to the interpretation of laboratory test results. It also leads to a differentiated approach for design by considering two types of behaviour process: 1) in the inner shell, i.e. the direct vicinity of openings, the failure mode is dominated by tensile cracking leading to spalling and related geometric dilation processes and 2) in the outer shell, i.e. remote from excavations, where confinement promotes interlock, we suggest that rock masses could be significantly stronger than predicted by standard approaches.

Original languageEnglish
Title of host publicationHarmonising Rock Engineering and the Environment - Proceedings of the 12th ISRM International Congress on Rock Mechanics
Pages855-860
Number of pages6
Publication statusPublished - Feb 13 2012
Externally publishedYes
Event12th International Congress on Rock Mechanics of the International Society for Rock Mechanics, ISRM 2011 - Beijing, China
Duration: Oct 18 2011Oct 21 2011

Publication series

NameHarmonising Rock Engineering and the Environment - Proceedings of the 12th ISRM International Congress on Rock Mechanics

Conference

Conference12th International Congress on Rock Mechanics of the International Society for Rock Mechanics, ISRM 2011
CountryChina
CityBeijing
Period10/18/1110/21/11

Fingerprint

Rocks
rock
shell
spalling
Spalling
dilation
failure mechanism
Excavation
Failure modes
rupture
excavation
laboratory
in situ
cracking (fracture)
laboratory test

Keywords

  • Rock properties
  • Site characterization

ASJC Scopus subject areas

  • Geology
  • Geotechnical Engineering and Engineering Geology

Cite this

Valley, B., Kim, B. H., Suorineni, F. T., Bahrani, N., Bewick, R. P., & Kaiser, P. K. (2012). Influence of confinement dependent failure processes on rock mass strength at depth. In Harmonising Rock Engineering and the Environment - Proceedings of the 12th ISRM International Congress on Rock Mechanics (pp. 855-860). (Harmonising Rock Engineering and the Environment - Proceedings of the 12th ISRM International Congress on Rock Mechanics).

Influence of confinement dependent failure processes on rock mass strength at depth. / Valley, Benoît; Kim, Bo Hyun; Suorineni, Fidelis T.; Bahrani, Navid; Bewick, Rob P.; Kaiser, Peter K.

Harmonising Rock Engineering and the Environment - Proceedings of the 12th ISRM International Congress on Rock Mechanics. 2012. p. 855-860 (Harmonising Rock Engineering and the Environment - Proceedings of the 12th ISRM International Congress on Rock Mechanics).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Valley, B, Kim, BH, Suorineni, FT, Bahrani, N, Bewick, RP & Kaiser, PK 2012, Influence of confinement dependent failure processes on rock mass strength at depth. in Harmonising Rock Engineering and the Environment - Proceedings of the 12th ISRM International Congress on Rock Mechanics. Harmonising Rock Engineering and the Environment - Proceedings of the 12th ISRM International Congress on Rock Mechanics, pp. 855-860, 12th International Congress on Rock Mechanics of the International Society for Rock Mechanics, ISRM 2011, Beijing, China, 10/18/11.
Valley B, Kim BH, Suorineni FT, Bahrani N, Bewick RP, Kaiser PK. Influence of confinement dependent failure processes on rock mass strength at depth. In Harmonising Rock Engineering and the Environment - Proceedings of the 12th ISRM International Congress on Rock Mechanics. 2012. p. 855-860. (Harmonising Rock Engineering and the Environment - Proceedings of the 12th ISRM International Congress on Rock Mechanics).
Valley, Benoît ; Kim, Bo Hyun ; Suorineni, Fidelis T. ; Bahrani, Navid ; Bewick, Rob P. ; Kaiser, Peter K. / Influence of confinement dependent failure processes on rock mass strength at depth. Harmonising Rock Engineering and the Environment - Proceedings of the 12th ISRM International Congress on Rock Mechanics. 2012. pp. 855-860 (Harmonising Rock Engineering and the Environment - Proceedings of the 12th ISRM International Congress on Rock Mechanics).
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