Fracture and Time-Varying Multifractal Behaviors of Single-Flawed Red Sandstone with Different Wavilness Angles

Abstract

To study the cracking behaviors and deformation damage process of single-flawed red sandstone with different wavilness angles, a series of uniaxial compression tests are conducted to investigate the effect of wavilness angles on the mechanical characteristics of the flawed red sandstone as well as crack initiation modes and ultimate failure modes. The real-time cracking behaviors of single-flawed red sandstone specimens with different wavilness angles are monitored using acoustic emission (AE) and photographic capturing technologies. The relationship among the AE rate curve, axial stress-time curve, and cracking process is constructed to evaluate the macroscopic deformation characteristics of preflawed rock. Moreover, the deformation damage process of single-flawed red sandstone with different wavilness angles is studied by using multifractal theory. A quantitative criterion is developed based on multifractal parameters of the AE time series, and the combined application of multifractal parameters can be considered as a precursor in the deformation and fracture damage process of flawed rocks.