Failure Mechanism and Acoustic Emission Characteristics of Rock Specimen with Edge Crack Under Uniaxial Compression

Abstract

There are many cracks in rock mass which have a significant influence on the stability of rock engineering. Most of current researches on the failure mechanism of cracked rock are mainly focused on the internal cracks. However, edge cracks around underground openings are common in many engineering fields. Understanding the failure mechanism of rock with edge cracks is essential to assess the stability of underground structures. Rock failure is closely related to the cracking processes and acoustic emission characteristics is deemed as an effective means of monitoring the cracking processes of rock. In this study, a series of numerical simulations utilizing particle flow software PFC2D were performed to investigate the influence of the length and position of edge crack on the failure mechanism and acoustic emission characteristics of rock specimens with edge cracks under uniaxial compression. The results show that: the strength of specimens is sensitive to the change of crack length and position; the directions of crack propagation in each specimen is in good agreement, the different crack tip position and the specimen boundary lead to different failure modes; the influence of crack length on acoustic emission is greater than that of crack position.