EAAI Journal 2026 Journal Article
Fusing acoustic emission and deep learning for automatic identification of progressive rock fracture
- Tongxiaoyu Wang
- Jiang Xiao
- Xiao Wang
- Sen Zhang
- Xiaofei Li
- Yujiang Liu
- Wenkai Bai
- Jianjun Wu
Accurate and continuous identification of progressive rock fracture stages is critical for instability early warning in geotechnical engineering. Traditional acoustic emission (AE) parameters often fail to fully characterize the nonlinear and dynamic nature of rock failure. This study proposes a data-driven framework integrating Mel-frequency cepstral coefficients (MFCCs) with a hybrid deep learning model for automatic, point-wise recognition of fracture stages. Full-waveform AE signals from sandstone under uniaxial compression were transformed into MFCC sequences and synchronized with normalized stress. MFCC-3 showed the strongest correlation with stress (Pearson r = 0. 52) and served as the optimal spectral descriptor. A convolutional neural network (CNN)-Transformer-bidirectional gated recurrent unit (BiGRU) hybrid model was developed to extract local time-frequency features, capture long-range dependencies, and model bidirectional temporal dynamics. Evaluated on 35, 318 time-aligned samples via stratified five-fold cross-validation, the model achieved a mean accuracy of 96. 95% (±0. 15%) and a macro-F1 score of 0. 97, significantly outperforming baseline models as confirmed by statistical testing. Ablation studies verified each module's contribution and the robustness of MFCC-3. Interpretability analyses revealed physically meaningful decision patterns, and early-warning evaluation reliably identified unstable crack propagation approximately 27. 5% of the loading duration prior to peak stress. The experiments were conducted under controlled laboratory conditions (sandstone, uniaxial compression); further validation in complex in-situ environments and diverse lithologies is required. This work establishes a transparent and extensible foundation for intelligent AE-based monitoring of progressive rock fracture.