Techno Press
Techno Press

Geomechanics and Engineering   Volume 12, Number 6, June 2017, pages 919-933
DOI: http://dx.doi.org/10.12989/gae.2017.12.6.919
 
Strength failure behavior of granite containing two holes under Brazilian test
Yan-Hua Huang, Sheng-Qi Yang and Chun-Shun Zhang

 
Abstract     [Full Text]
    A series of Brazilian tests under diameter compression for disc specimens was carried out to investigate the strength and failure behavior by using acoustic emission (AE) and photography monitoring technique. On the basis of experimental results, load-displacement curves, AE counts, real-time crack evolution process, failure modes and strength property of granite specimens containing two pre-existing holes were analyzed in detail. Two typical types of load-displacement curves are identified, i.e., sudden instability (type I) and progressive failure (type II). In accordance with the two types of load-displacement curves, the AE events also have different responses. The present experiments on disc specimens containing two pre-existing holes under Brazilian test reveal four distinct failure modes, including diametrical splitting failure mode (mode I), one crack coalescence failure mode (mode II), two crack coalescences failure mode (mode III) and no crack coalescence failure mode (mode IV). Compared with intact granite specimen, the disc specimen containing two holes fails with lower strength, which is closely related to the bridge angle. The failure strength of pre-holed specimen first decreases and then increases with the bridge angle. Finally, a preliminary interpretation was proposed to explain the strength evolution law of granite specimen containing two holes based on the microscopic observation of fracture plane.
 
Key Words
    granite; two pre-existing holes; disc specimen; tensile strength; crack coalescence
 
Address
(1) Yan-Hua Huang, Sheng-Qi Yang:
State Key Laboratory for Geomechanics and Deep Underground Engineering, School of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou 221116, P.R. China;
(2) Chun-Shun Zhang:
Department of Civil Engineering, Monash University, Clayton, VIC 3800, Australia.
 

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