Experimental and Numerical Studies of Brittle Rock-Like Samples with Internal Open Fractures and Cavities Under Uniaxial Compression

Previous laboratory tests conducted using rock-like samples with 2D through fractures are mostly high-level simplifications of real engineering conditions. Thus, the results from these 2D analyses cannot usually be successfully applied to 3D conditions and real engineering conditions. To study the mechanical properties and failure processes of samples that could highly represent the 3D conditions in the real world, brittle rock-like samples with designed internal open-type fractured structures are prepared for this study using the volume loss method and super absorbent polymer, and following studies included the uniaxial compression tests and discrete element numerical simulations. The results from real tests and simulations proved that the shape, position, and volume of internal open-type fractured structures had an obvious influence on the physical properties and spatial distributions of shear and tensile failures of specimens. Different from the results obtained by former 2D studies, failure surfaces in this work are not parallel with the preset structures, and the main failure faces develop along the diagonal directions of the internal structure. In addition, the tensile failure distribution is controlled by the shape and position of the internal structure, and the shear failure distribution is influenced by the height of the internal structure and the positions of the tensile failure surface. The findings are helpful for explaining the failure characteristics of specimens containing 3D fractured structures.