Stress corrosion and interaction behaviour of adjacent cracks in rock-like material under hydro-mechanical Coupling: An experimental and numerical study

Abstract

Under long-term hydro-mechanical coupling, the propagation of adjacent cracks present obvious time effect, and have significant influence on the progressive failure mode of rock-like materials. The creep tests were carried out based on the cement mortar specimen containing adjacent cracks, and the low-field Nuclear Magnetic Resonance (NMR) technology were used to evaluate the evolution of crack structure in the specimen. Based on the numerical simulation, the influences of the interaction behaviour between cracks on the time-dependent propagation of cracks and failure of specimens is revealed. The results show that: The specimen presents a tension-shear failure mode, and the macro fracture on its surface is Z-shaped; Crack interaction has an important role in promoting the formation and connection of microcracks, which increases the number of seepage channels and promotes the formation of the macro fracture; The propagation of adjacent cracks show significant asymmetry and non-uniformity, due to the stress superposition effects in the rock bridge area; The interaction between cracks is manifested as the inhibition of wing crack propagation in the rock bridge area at the initiation stage and then promotion effect at the later stage.