On the Fatigue Mechanical Responses of Pre‐Fissured Marble Considering Rock Bridge Angle Subjected to Uniaxial Cyclic Loading: A Lab‐Scale Investigation

The aim of this work is to investigate the influence of rock bridge angle (RBA) on the fatigue mechanical behaviors of double fissure contained marble samples. The marble samples were prepared with RBA of 45°, 75°, 105°, and 135°, respectively. Testing results show that volumetric deformation from dominant compression to dominant expansion is impacted by the RBA. The instability prediction is earlier using the volumetric strain rate than the volumetric strain. In addition, acoustic emission analysis reveals that the released energy is higher for rock with larger RBA than that of low RBA; damage at the stress‐increasing stage is larger than the cyclic loading stage. Moreover, failure transits from tensile to shear mode. It is found that tensile‐dominant failure mode is for rock with low RBA; however, shear‐dominated failure mode occurs when RBA is relatively large, leading to complex crack networks. It is suggested that stress shielding effect is for high RBA sample resulting in enhancing resistance to failure.