Influence of creep–slip fracture length on the local deformation field and fracture characteristics of rock-like models

Abstract

Investigating the influence of creep–slip behavior on the deformation and faulting development near the fracture is essential for elucidating the deformation and failure mechanism of fractured rock masses. In this study, uniaxial compression experiments were conducted on rock-like models with different creep–slip fracture lengths prefabricated from gypsum, quartz sand, and barite powder. The experimental results showed that both the uniaxial compressive strength and elastic modulus of models diminished as fracture length increased. Based on the stress–strain curve characteristics, the model deformation process could be divided into four stages: medium compaction stage, elastic deformation stage, crack propagation stage, and failure stage. The fracture modes of the model were wing cracks and anti-wing cracks, and the degree of crack development increased with the increase in the fracture length. The distribution location of the local peak maximum principal strain was not fixed. The local strain deflection angle exhibited significant regional characteristics. The peak value of the relative displacement rate decreased with increasing fracture length. The acoustic emission hit count rate of models with a small fracture length increased significantly after entering the crack propagation stage. Microfracture events on the active loading plate increased and became more dispersed with increasing fracture length. These findings can serve as a basis for better understanding the failure characteristics of geological bodies, particularly in the context of geotechnical engineering.