## 4 Results  
### Effect of Stress Disturbance  
#### 4.1.1 Surrounding Rock Stress of Main Inclined Shaft without Excavation Disturbance  
Figures 7-10 show that the main inclined shaft is not disturbed by excavation, and the plastic zone range, anchor structural unit, stress distribution in the Z direction and Y direction of the four monitoring areas of the model section are taken. The analysis of the Mohr-Coulomb envelope shows that the structural unit of the plastic zone is formed by the influence of stable stress. For X (10, 12), the structural unit near the central axis of the roadway floor is the tensile force unit, and the structural units of the roadway side and roof are subject to shear force. Under the influence of shear force, a large-scale plastic zone appears in the strata under the roadway. The stress of the anchor cable is above 4.0 \(\times\) 10\({}^{7}\) Pa, and the stress of the anchor bolt is about 2.0 \(\times\) 10\({}^{7}\) Pa. The vertical principal stress of the roadway floor is 1.8232 \(\times\) 10\({}^{5}\) Pa. The maximum shear stress of the two sides is 6.0 \(\times\) 10\({}^{6}\) Pa, mostly concentrated in the bottom of the side. Figure 6: Model design and measuring point arrangement. Figure 7: Plastic zone range of the four monitoring areas without excavation disturbance. Figure 8: Cable force of the four monitoring areas without excavation disturbance. Figure 10: Y\(-\)direction stress distribution of the four monitoring areas without excavation disturbance. Figure 9: Z\(-\)direction stress distribution of the four monitoring areas without excavation disturbance. For X (25, 27), the plastic zone range of roadway-surrounding rock increases, and the plastic zone affected by the shear force increases. The structural units near the central axis of the roadway floor are subjected to tensile tension and shear force, and the structural units of roadway side and roof are mostly subjected to shear force. The stress of the anchor cable is about 1.5 \(\times\) 10\({}^{7}\) Pa, the stress range of the anchor bolt is about 2.5 \(\times\) 10\({}^{6}\) Pa\(\sim\)2.5 \(\times\) 10\({}^{7}\) Pa, and the maximum stress is the bottom angle anchor of the two roadways. The maximum vertical principal stress of roadway floor is 1.6896 \(\times\) 10\({}^{5}\) Pa. The maximum shear stress of the two roadways is 6.0453 \(\times\) 10\({}^{5}\) Pa, mostly concentrated in the surrounding rock of the roadway floor. For X (50, 52), the plastic zone range of roadway-surrounding rock increases with the depth, and the maximum principal stress gradually changes from tensile stress to shear stress. The structural unit of roadway floor is affected by tensile stress and shear stress and does not reach a stable state. The structural unit of roadway side and roof is also affected by tensile stress and shear stress. The maximum stress of the anchor cable is 4.0067 \(\times\) 10\({}^{7}\) Pa, and the stress range of the anchor rod is \(-\)1.1967 \(\times\) 10\({}^{7}\) Pa\(\sim\)2.5 \(\times\) 10\({}^{7}\) Pa, which is uniform. The vertical principal stress of the roadway floor is 2.8301 \(\times\) 10\({}^{4}\) Pa, and the maximum vertical principal stress of the roadway side is \(-\)2.8947 \(\times\) 10\({}^{7}\) Pa. From this analysis, it can be concluded that the floor heave is easily caused by vertical stress. The maximum shear stress of the two sides is \(-\)2.5340 \(\times\) 10\({}^{7}\) Pa, and the shear stress decreases to \(-\)1.8942 \(\times\) 10\({}^{5}\) Pa near the bottom corner of the two sides. For X (67, 69), the plastic zone range of roadway-surrounding rock did not change significantly, and the maximum principal stress was shear stress. The stress form of roadway-surrounding rock structure unit changes, which is mainly caused by unstable stress. The maximum stress of the anchor cable is 3.7178 \(\times\) 10\({}^{7}\) Pa, and the stress range of the anchor rod is \(-\)4.0161 \(\times\) 10\({}^{6}\) Pa\(\sim\)2.5 \(\times\) 10\({}^{7}\) Pa, which is uniform.