Time–Space Joint Response Characteristics of Acoustic Emission and Strain of Coal Damage Evolution

The occurrence of rockburst disasters is closely related to the zonal deformation and failure of rock masses. To effectively monitor and understand the critical zones of surrounding rock damage, it is imperative to establish an extensive network of strain measurement stations. In this study, a comprehensive approach was adopted, integrating acoustic emission (AE), digital image correlation, and fiber Bragg grating demodulation techniques. According to the different deformation stages of the sample, the changes in AE counts and internal strains were analyzed, and the position changes of the AE event location, internal high-strain field, and surface-high-strain field were analyzed, and it was found that there was good spatial correlations among them. Based on the AE events’ counts and localization and internal strain, two new damage variables were proposed, and their numerical values and positions were used to analyze the evolution path of coal sample damage, which was found to match the actual fracture area of the specimen. Therefore, a novel comprehensive monitoring method combining the localization of AE events and internal strain fields is proposed to determine the position of high-damage areas. These research findings are of significant importance for accurately predicting the key areas leading to overall instability in coal–rock masses.