Review on acoustic emission characteristics of rock fractures undergoing shear

Abstract

Comprehending the shear behavior of rock fractures plays a vital role in reducing risks in underground rock engineering. An extensively utilized experimental method to investigate this issue is the direct shear tests of fractured rock specimens under a variety of mechanical conditions. Acoustic emission (AE) monitoring, as a powerful tool, can provide real-time insights into the cracking and failure processes during shear tests. In recent decades, a multitude of studies delved into the AE characteristics in rock shear testing, and demonstrated that AE responses were strongly correlated with initiation and propagation of microcracks. Various methods focusing on waveform or amplitude characteristics of AE signals have been developed to interpret AE data, linking AE parameters to shear behaviors of rock fractures. In this review, the previous achievements on AE responses during direct shear tests on rock fractures are first summarized, and a unified method is proposed to reinterpret the representative data and better understand the correlation between AE parameters and the shear strength of rock fractures. The results highlight the potential of AE monitoring for predicting rock failure and improving the safety of underground rock engineering. Finally, the developments and challenges of AE monitoring techniques and interpretation models in fractured rocks are emphasized.

Keywords

Direct shear test / Rock fracture / Acoustic emission / Shear strength / Interpretation method

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