## 5 How the Surrounding Rock Reacts Mechanically When a Roadway Is Being Dug Under Tectonic Stress
### Model Construction  
Utilizing the engineering geological conditions and in situ stress field test findings, FLAC\({}^{\text{3D}}\) software was employed to simulate the mechanical response of the surrounding rock during the excavation of the 1232(3) transport route under tectonic stress circumstances. Figure 10 shows the plan for the simulated excavation of the working face. There are two stages to digging out the 1232(3) transportation roadway: the rock roadway stage and the gob-side stage. This section mostly looks at how the surrounding rock reacts mechanically at six points: 50 m along the roadway, 20 m along the roadway, 5 m along the roadway, 5 m along the gob, 20 m along the gob, and 50 m along the gob. Distribution of Horizontal Stress in Different Places in the Rock Around the Roadway Under Tectonic Stress  
Figure 11 shows the horizontal stress distribution cloud diagram for different parts of the roadway that was made using a computer simulation. Figure 11a-c shows that the 1232(3) transport roadway is in the stage along the roadway. The horizontal stress reduction zone appears in the shallow rock layer around the roadway as it gets closer to the goat. The horizontal stress concentration zone appears in the deep rock layer of the roof. The top horizontal stress concentration zone relocates to the solid coal side. The horizontal stress in the deep rock layers that make up the roof of the 1232(3) transport roadway seems to be going up a little bit at first and then going down. Figure 11d-f illustrates that, in the gob-side stage of the 1232(3) transportation roadway, the pressure relief range of the goat adjacent to the coal pillar progressively expands, while the concentration of horizontal stress on the roadway roof diminishes gradually. The horizontal stress concentration zone of the roof penetrates into the deeper strata of the surrounding rock. A little concentration of horizontal tension exists inside the deep rock strata of the floor. The horizontal stress on the solid coal side is markedly greater than that on the coal pillar side. After the excavation of 1232(3) transportation roadway is finished, the stress monitoring path is placed horizontally along the vertical roadway roof position, based on the model calculation results. This provides the horizontal stress distribution curves at different positions on both sides of the roadway roof, as shown in Figure 12.  
Figure 11: Horizontal stress distribution nephogram of roadway surrounding rock in different stages. (**a**) 50 m along roadway (**b**) 20 m along roadway (**c**) 5 m along roadway (**d**) 5 m along gob (**e**) 20 m along gob (**f**) 50 m along gob. Figure 10: Working face simulation excavation scheme. Figure 12 shows that the horizontal stress on the 1232(3) transportation roadway is approximately evenly spread out across the roadway stage, with a peak value of 33 MPa. The peak value of horizontal stress on the coal pillar side is 10 MPa, which is lower than the peak value of horizontal stress on the solid coal side. When the roadway is between 5 m along the roadway side and 5 m along the goat side, the horizontal stress on the coal pillar side goes up as the roadway enters the goat stage. The peak value of the horizontal stress goes up to 13 MPa. The goal's pressure relief range is getting bigger, and the horizontal stress on the goat's side is going down to 10 MPa. The horizontal stress on the solid coal side of the gob-side stage of 1232(3) transportation roadway does not change much from the roadway stage. However, the horizontal stress on the coal pillar side goes up even more, reaching a peak value of 15 MPa. As shown in the analysis above, the stress concentration degree on the solid coal side does not change much from the roadway stage to the gob-side stage. However, the stress concentration degree on the coal pillar side is getting higher. The locus of maximum tension on the coal pillar's side progressively transitions towards its center.