Distinct element numerical simulation of acoustic emission characteristics during failure process of transversely isotropic rock subjected to uniaxial compression

This paper presents an investigation into the failure process of transversely isotropic rock with different orientation angles by distinct element method. Results show that the difference in orientation angle of transversely isotropic rock results in various acoustic emission characteristics. Acoustic emission characteristics are related to stress state. Spatial response of acoustic emission occurs mainly at the interface. Due to the composite material properties of transversely isotropic rock,the complex relationship of stress and strain results in the interface becoming the most likely zone where cracks may first initiate and then propagate. The propagation of cracks expands into the nearby area and then causes macro-cracks to be formed,and finally results in the total failure of the entire specimen. Because of the different physical-mechanical properties of transversely isotropic rock,a complex stress state develops near the interface,including stress concentrations. Moreover,the orientation angle induces shear stress near the interface. Therefore, the interface becomes the most probable location of crack initiation and propagation. The initiation locations of cracks and propagation models largely determine the final failure pattern and are often tightly related with the interfaces.