Fracture behaviour of central-flawed rock plate under uniaxial compression

• Published in: Theoretical and applied fracture mechanics Vol. 106; p. 102503
• Main Authors: Wang, Yixian, Zhang, Hui, Lin, Hang, Zhao, Yanlin, Liu, Yan
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01.04.2020; Elsevier BV
• Subjects: Compression zone; Computer simulation; Crack initiation; Crack initiation mechanism; Crack propagation; Engineering geology; Failure analysis; Finite element method; Fracture behavior; Granite specimen; Inclination angle; Mechanical properties; Mountain tunnels; Simulation; Tensile stress; Wing crack; Wing crack; Granite specimen; Fracture behavior; Crack initiation mechanism; Crack propagation
• ISSN: 0167-8442; 1872-7638
• DOI: 10.1016/j.tafmec.2020.102503

•Laboratory test of granite specimens containing both holes and flaws under uniaxial compression was carried out.•The relationship between flaw inclination angle and mechanical characteristics was investigated.•Initiation mechanism of wing crack was analyzed by theoretical method and XFEM simulation. Fault fracture zone is a common engineering geological condition in mountain tunnel excavation, which often brings great difficulties to engineering construction. Thus, uniaxial compression experiments were carried out on the granite specimens with a central hole and hole edge flaws to investigate such engineering problems. And the crack initiation mechanism was studied by theoretical analysis and Extended Finite Element Methods (XFEM) simulation. The experimental results show that the mechanical parameters and crack types of the specimens distinctly vary with the flaw inclination. The mechanical properties of specimens such as strength are greatly weakened by the central hole and hole edge flaws compared with those of intact specimens, and the weakening effect decreases gradually with the increase of flaw inclination angle. When the inclination angle of flaw is small, the proportion of tensile cracks is high, resulting in tensile failure of specimens. While as the inclination angle of flaw increases, shear cracks gradually dominate, leading to shear failure in the specimen. In addition, the results of theoretical analysis and numerical simulation show that the wing crack initiation angle that appeared in the experiment are completely consistent with the theoretical and simulation results. And it is suggested by numerical results that the tensile stress at the flaw tip of specimens with flaw inclination angle of 15° and 75° is lower than that of other specimens, which may cause the absence of wing cracks.