Fracture Processes of Rock-Like Specimens Containing Nonpersistent Fissures under Uniaxial Compression

Miao Chen; Shengqi Yang; Ranjith Pathegama Gamage; Wendong Yang; Pengfei Yin; Yuanchao Zhang; Qiangyong Zhang

doi:10.3390/en12010079

Energies (Dec 2018)

Fracture Processes of Rock-Like Specimens Containing Nonpersistent Fissures under Uniaxial Compression

Miao Chen,
Shengqi Yang,
Ranjith Pathegama Gamage,
Wendong Yang,
Pengfei Yin,
Yuanchao Zhang,
Qiangyong Zhang

Affiliations

Miao Chen: State Key Laboratory for Geomechanics and Deep Underground Engineering, School of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou 221116, China
Shengqi Yang: State Key Laboratory for Geomechanics and Deep Underground Engineering, School of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou 221116, China
Ranjith Pathegama Gamage: State Key Laboratory for Geomechanics and Deep Underground Engineering, School of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou 221116, China
Wendong Yang: College of Pipeline and Civil Engineering, China University of Petroleum, Qingdao 266580, China
Pengfei Yin: State Key Laboratory for Geomechanics and Deep Underground Engineering, School of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou 221116, China
Yuanchao Zhang: State Key Laboratory for Geomechanics and Deep Underground Engineering, School of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou 221116, China
Qiangyong Zhang: Research Center of Geotechnical and Structural Engineering, Shangdong University, Jinan 250100, China

DOI: https://doi.org/10.3390/en12010079
Journal volume & issue: Vol. 12, no. 1
p. 79

Abstract

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Many rock engineering accidents have proven that the coalescence of discontinuities in surrounding rock can have a major impact on the security and stable operation of energy infrastructure. To give an insight into the understanding of the crack propagation and coalescence in fissured rock masses, a series of uniaxial compression experiments were conducted on rock-like specimens containing nonpersistent fissures. The digital speckle correlation method (DSCM) and the acoustic emission (AE) monitoring system were adopted to capture the real-time strain field on the specimens’ surfaces and microfracturing events within specimens, respectively. The experimental results indicated that the strength and deformation modulus of specimens were significantly affected by fissure inclination. The damage process showed obvious progressive stain localization failure characteristics. The clear and intuitive full-field strain field development was successfully monitored by the DSCM technique. The real-time strain accumulation, crack initiation, propagation, and coalescence were also analyzed. Each time, the saltation of the strain field was usually accompanied by the fluctuation of the stress curve and obvious AE events. Crack coalescence modes between fissures changed from tension coalescence mode to mixed tension-shear coalescence mode, then to shear coalescence mode with an increase in fissure inclination. Five basic failure modes were identified from the experimental results: Tensile failure across the fissure planes, rotation failure of newly generated blocks, mixed failure mode, shear failure, and splitting failure. An investigation of the fracture processes of rock-like specimens containing nonpersistent fissures using these methods can enhance understanding of the fracture behavior of jointed rocks.

Published in Energies

ISSN: 1996-1073 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Technology
Website: http://www.mdpi.com/journal/energies

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