## 5 Engineering Practice
### Analysis of Monitoring Results  
The roof deformation of the 9306 working face at different burial depths is shown in Figure 12a. The analysis reveals that as the working face advances, the vertical displacement of the roof exhibits a gradual increase, followed by a sharp increase, and finally stabilizes. The peak vertical displacements of the three monitored sections are all located on the roof-cutting side and gradually increase with increasing burial depth, with values of 159 mm, 172 mm, and 185 mm, respectively. These values are similar to the numerical simulation results of 182 mm, 185 mm, and 194 mm, with an error rate maintained between 5% and 14%. Notably, when compared to the designed height of the roadway of 2.2 m, the maximum roof deformation accounts for approximately 8.4%, indicating that the deformation of the roof at different burial depths has been effectively controlled through reasonable roof-cutting parameters.  
The stress on the roof anchor cables on the roof-cutting side in different buried depth sections of the 9306 working face is shown in Figure 12b. The analysis reveals that the stress on the anchor cables also exhibits a slow growth phase, a rapid growth phase, and then tends to stabilize, which is basically consistent with the roof movement state. Affected by the abutment pressure in front of the working face, the stress on the anchor cables gradually increases. As it gradually approaches the working face, influenced by the violent roof movement, the stress increase on the anchor cables gradually rises. After entering the entry retention section for 25 m, the stress on the anchor cables gradually begins to stabilize. The peak stress values of the anchor cables in the three monitoring sections also gradually  
Figure 11: Layout of surrounding rock stability monitoring for roof-cutting and entry retention roadways in different buried depth sections of the 9306 working face.  
Figure 12: Analysis of numerical simulation results of roof displacement and stress in GSER roadways with different buried depths: (**a**) monitoring of roof deformation in different buried depth sections; (**b**) monitoring of anchor cable forces on the roof-cutting side in different buried depth sections.  
increase with greater buried depth, reaching 184 KN, 200 KN, and 208 KN, respectively, all within the allowable range for anchor cable use. This indicates that reasonable roof-cutting parameters have basically achieved stress optimization of the retained roadway roof in different buried depth sections.  
The overall effect of the entry retention in the air intake roadway of the 9306 working face is shown in Figure 13. From the perspective of the on-site effect, the internal and external parts of the roadway roof, the roadside support body, and the solid coal rib are relatively intact, with no obvious issues such as roof delamination, local roof fragmentation, or damage to the roadside support. The overall effect of entry retention is relatively good, indicating that the stability control of the surrounding rock in the GSER has been achieved by adopting reasonable roof-cutting parameters in different buried depth sections. This verifies the rationality of the theoretical calculations, numerical analysis, and roof-cutting scheme mentioned earlier.  
Figure 13: The effect of entry retention in the air intake roadway of the 9306 working face in Anshun Coal Mine: (**a**) borehole inspection of the GSER roof; (**b**) effectiveness of roadside support in GSER; (**c**) and overall stability of the surrounding rock in GSER.