## 4 Analysis of Physical Similarity Simulation Experiment Results
### AE Monitoring Analysis  
Figure 10 presents the signals from the 1# AE sensor during the working face of the lower seam passing through the 1# failed TCP. The AE signals were not significant, with low AE energy and ringing counts. As the working face advanced, the immediate roof rock strata were damaged, leading to noticeable fluctuations in AE energy and ringing counts; however, the amplitude and energy values remained low. As the cantilever length of the IEBS increased, fissures within the rock strata developed. Around 123 s, a significant release of AE energy signals occurred, with noticeable fluctuations and a sharp change in ringing counts. The total number of events and signal intensity were high, which indicates that the fracture of the IEBS was accompanied by the fracturing of the roof OR, with maximum AE energy and ringing counts reaching 11,409/ms\(\cdot\)mV and 1255 counts/s, respectively. Subsequently, the AE energy and ringing counts within the model fluctuated occasionally but generally stabilized. Figure 8: Abutment pressure curve of working face during mining crossing interval coal pillar. Figure 7: The abutment pressure curves of the working face during mining in the first and second mining strips. Figure 11 illustrates the signal from the 4# AE sensor during mining under the ICP. As the working face advanced to the ICP, the immediate roof rock strata failed, resulting in noticeable fluctuations in AE energy and ringing counts, although the amplitude and energy values were not significant. As the cantilever length of the IEBS continued to increase, fissures within the rock developed. Between 140 and 300 s, frequent fluctuations in AE energy signals were observed, and a large amount of elastic energy was released from the surrounding rock. The AE energy and ringing counts fluctuated noticeably, with a high total number of events and signal intensity, indicating that along with the fracture instability of the IEBS, the OR underwent fracture and instability within a short period of time. During this stage, AE energy and ringing counts reached 13,887/ms\(\cdot\)mV and 2219 counts/s, respectively. After the OR caved, the AE energy and ringing counts within the model fluctuated occasionally but generally tended to stabilize. Figure 10: AE monitoring of the OR instability during mining under the 1# failed TCP. Figure 9: AP curves of working face during mining under the third and fourth mining strips. Figure 12 shows the characteristics of the AE signal from the 4# AE sensor during the fracture of the IRS as the working face passed through the ICP. As the working face advanced, the load per unit area on the IEBS continuously increased, and concentrated stresses developed on the ICP, leading to synchronous instability in the IRS. Between 120 and 180 s, the AE energy and ringing counts from the 4# AE sensor exhibited frequent fluctuations, with a significant release of AE energy, sharp changes in ringing counts, and a high total number of events and signal intensity. At the same time, under the action of the double-arch bridge structure in the ICP roof and the load of its OR, the IRS experienced synchronous cutting instability along the coal wall of the working face. During this stage, the maximum AE energy and ringing counts reached 16,598/ms\(\cdot\)mV and 2263 counts/s, respectively. After the OR fractured, while there were still some ongoing damages within the model, the AE energy and ringing counts fluctuated slightly but generally tended to stabilize. Figure 11: AE monitoring of the OR instability during mining under the interval coal pillar. Figure 13 illustrates the characteristics of the AE signal from the 4# AE sensor during the fracture of the IRS as the working face passed through the 2# failed TCP. Under the influence of the IEBS, the AE energy and ringing counts fluctuated, although the amplitude and energy values were not significant. Around 95 s, a sudden release of AE energy signals occurred, with noticeable fluctuations and sharp changes in ringing counts.