A novel quantitative explanation for the fracture mechanism of sandstone containing a circular inclusion

Abstract

In this study, uniaxial compressive tests combined with the digital image correlation (DIC) method are used to investigate the mechanical properties, fracture process, and failure pattern of sandstone containing a circular inclusion. A DIC‐based methodology is proposed to quantitatively explain the crack initiation and propagation mechanism. The identification criterion of crack type is presented based on the nature of cracks and the development trends of relative displacement. Three crack types, including tensile cracks, tensile–shear cracks, and shear cracks, with different cracking mechanisms are identified. The inhibitory effect of the inclusions on crack initiation and propagation is revealed. The inclusion–matrix debonding mechanism is further investigated, and it is found that the inclusion interface consists of tensile concentration zones on the left/right sides and compressive concentration zones on the top/bottom sides. The tensile concentration zone is the main reason for debonding of the inclusions from the sandstone matrix.

The Fracture Evolution Mechanism of Tunnels with Different Cross-Sections under Biaxial Loading

“…A multitude of tests have demonstrated that DIC technology is an effective means of characterizing the fracture and crack propagation of rock masses [21][22][23][24][25]. According to different crack mechanisms, the crack types can be divided into tensile crack, shear crack, and tensile-shear crack [26]. Zhou [27] conducted a failure study on marble specimens with rectangular cavities under uniaxial loading, and the main failure modes were splitting failure, shear failure, mixed tensile/shear failure, and surface spalling.…”