## 4 Field Application of Theoretical Results  
In order to demonstrate the above analysis, a field study site was selected at the 1252(1) longwall panel of a coal mine in China. The longwall panel extracted the 11-2 coal seam, which had an average thickness of 2.8 m, a dip angle of 2-3\({}^{\circ}\), and an f value of 1.8-2.5. The 1252(1) haulage gateway was excavated along the adjacent goat side of the 1252(1) longwall panel with a 5 m small coal pillar. The geological borehole profile and the haulage gateway layer in the 1252(1) longwall panel are illustrated in Figure 11.  
In order to meet the requirements of large-scale equipment and ventilation, a reasonable size for the haulage gateway was determined to be 4.9 m wide and 3.2 m high. A combined bolt-mesh-cable support was initially chosen, as shown in Figure 12; however, the width of the gateway shrank from 4.9 m to only 3.5 m after 65 days of excavation. Hence, a new effective support control was suggested in order to continue excavation. Figure 11: Geological borehole profile and the haulage gateway layer in the 1252(1) longwall panel. Figure 10: Relationships between the thickness of the thin rectangular plate (_a_), the critical width, and the critical height of the goat-side entry. Taking into account the specific geological conditions, combined with field and laboratory test data, the parameters of the surrounding rock structure of the 1252(1) haulage gateway were as follows: \(L\) = 4.9 m, \(q_{1}\) = 21.25 MPa, \(E\) = 3.97 GPa, \(\mu\) = 0.28, \(h\) = 3.2 m, \(x_{0}\) = 6.0 m, \(x_{1}\) = 5.0 m, and \(x_{2}\) = 0.5 m. After substituting these parameters into Equation (15), the critical thickness of the thin rectangular plate of the small coal pillar in the 1252(1) haulage gateway without support was calculated to be 0.1 m. This meant that alternative supporting methods need to be applied, either by enhancing the integrity and strength of the small coal pillar or by diverting the stress load on it. Therefore, cable beams were introduced in the roof to reduce the abutment pressure on the small coal pillar. Simultaneously, more side cables were added to strengthen the coal pillar and improve its integrity. The revised configuration for the combined bolt-mesh-cable support is shown in Figure 13. In addition, the small coal pillar was also cemented by shotcrete-closed lags 30 m behind the excavating face and was reinforced by grouting using 525# sulfoaluminate cement to further enhance its integrity. With the new supporting parameters, the deformations of the surrounding rock in the 1252(1) haulage gateway were effectively controlled. The average sidewall-to-sidewall displacement was 225.8 mm and the average roof-to-floor displacement was 385.8 mm. The average subsidence of roof was 57.3 mm. The support effects in the areas 100 m behind the tunnelling face are shown in Figure 14. The section size of the 1252(1) haulage gateway fully met the requirements of the working face. In particular, the integrity and stability of the small coal pillar was significantly improved under the enhanced support of the side cable. The average sidewall-to-sidewall displacement was reduced by about 83.87% compared to the deformation observed under the initial support on the two sides. The revised combined support scheme proposed by analyzing the structural stability and the integrity of the surrounding rock for GESCP was found to be feasible. Figure 12: Sketch of the initial combined bolt-mesh–cable support. Figure 14: Support effects in the haulage gateway. Figure 13: Sketch of the revised combined bolt-mesh-cable support. Based on the analysis of the structural stability and the integrity of the surrounding rock for GESCP, the surrounding rock of the 1252(1) haulage gateway was controlled by strengthening support. More research about the structural stability of the GESCP should be studied in the future.