Mechanical properties of expansive slurry fractured rock mass composites in the direct shear experiment

摘要

To study the differences in the mechanical properties and the strength variation of the expansive slurry-fractured rock mass composites (ESFC) with different slurry thicknesses, initial normal stresses, and fracture roughness, the direct shear experiment was carried out. The internal damage evolution trend was analyzed using the acoustic emission (AE) and digital image correlation (DIC) methods. The results show that: (1) With increasing the slurry thickness, the initial normal stress, and the fracture roughness, the shear strength of the ESFC was increased and their growth trends of strength were "log-like", "linear-like", and "exponential-like" respectively. (2) ESFC with different slurry thicknesses, initial normal stresses, and fracture roughness showed similar failure modes. These failure modes resembled a "ladder" distribution primarily along the tensile fracture of the expansive slurry and the deformation of the slurry-rock interface. (3) An increase in the slurry thickness, the initial normal stress, and the fracture roughness enhanced the friction at the slurry-rock interface, which improved the shear strength of ESFC. However, their shear mechanical properties were different.

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