Study on the fracture behavior of prefabricated fissures granite based on DIC and laser scanning techniques

摘要

The initiation, propagation, and coalescence of cracks in the rock bridge are the root causes of rock failure. However, the identification of cracks propagation paths is a problem in rock mechanics. This paper studies the evolutionary law of the strain field in the rock bridge region of granite with pre-fissures using 3D-DIC after equivalence and simplification. Based on the real crack initiation mechanism of "relative slip between regions" proposed in this paper, combined with the priority order of crack propagation at the edge of the rock bridge, the pattern of cracks propagation and coalescence was obtained. We analyze the fracture characteristics in roughness and morphology to verify the validity of the proposed mechanism. The tensile and shear failure areas around the rock bridge were identified quantitatively, and the roughness, fractal dimension, and energy consumption of the sections formed by tensile failure and shear failure are different.