Multi-source information response characteristics of surrounding rock catastrophic instability in deep roadways with four-dimensional support

As coal mining progresses to greater depths, controlling the stability of surrounding rock in deep roadways has become an increasingly complex challenge. Although four-dimensional (4D) support theoretically offers unique advantages in maintaining the stability of rock mass, the disaster evolution processes and multi-source information response characteristics in deep roadways with 4D support remain unclear. Consequently, a large-scale physical model testing system and self-designed 4D support components were employed to conduct similarity model tests on the surrounding rock failure process under unsupported (U-1), traditional bolt-mesh-cable support (T-2), and 4D support (4D-R-3) conditions. Combined with multi-source monitoring techniques, including stress–strain, digital image correlation (DIC), acoustic emission (AE), microseismic (MS), parallel electric (PE), and electromagnetic radiation (EMR), the mechanical behavior and multi-source information responses were comprehensively analyzed. The results show that the peak stress and displacement of the models are positively correlated with the support strength. The multi-source information exhibits distinct response characteristics under different supports. The response frequency, energy, and fluctuations of AE, MS, and EMR signals, along with the apparent resistivity (AR) high-resistivity zone, follow the trend U-1 > T-2 > 4D-R-3. Furthermore, multi-source information exhibits significant differences in sensitivity across different phases. The AE, MS, and EMR signals exhibit active responses to rock mass activity at each phase. However, AR signals are only sensitive to the fracture propagation during the plastic yield and failure phases. In summary, the 4D support significantly enhances the bearing capacity and plastic deformation of the models, while substantially reducing the frequency, energy, and fluctuations of multi-source signals.