## 3 Results and Analysis
### The Influence of Thermal Conductivity on the Temperature Field of Surrounding Rock  
Figure 5 depicts the spatial distribution curve of the dimensionless temperature of the roadway-surrounding rock under varying thermal conductivity. The change curve of the dimensionless temperature of the surrounding rock with a dimensionless radius is mainly consistent with the observations mentioned above. Simultaneously, as thermal conductivity increases, the dimensionless temperature of the surrounding rock near the roadway wall gradually rises, while the dimensionless temperature of the surrounding rock farther from the roadway wall gradually decreases. As an illustration, considering \(R=0\) and \(R=1\), when ventilated for 31 days with an increase in thermal conductivity  
Figure 4: The relationship curve between dimensionless temperature and dimensionless time. Figure 3: The relationship curve between dimensionless temperature and dimensionless radius. from 1 W/(m\(\cdot\)K) to 3 W/(m\(\cdot\)K), the dimensionless temperature of the surrounding rock at \(R=0\) decreased by 91%, 90%, and 85%, respectively, compared to the original temperature. Simultaneously, the dimensionless temperature of the surrounding rock at \(R=1\) decreased by 6%, 13%, and 17%, respectively, compared to the VRT. Regarding the observations above, reference [29] provides a clear explanation. With the increase in the thermal conductivity of the surrounding rock, the heat conduction intensity within the surrounding rock gradually increases, as does the convective heat transfer intensity between the roadway wall and the airflow. However, the heat convection intensity surpasses the heat conduction intensity, leading to more significant heat loss from the roadway wall than the heat supply. As a result, the temperature drop rate gradually decreases with the increase in thermal conductivity, while the temperature drop rate inside the surrounding rock increases with the increase in thermal conductivity. Additionally, the increase in thermal conductivity can extend the cooling range of the surrounding rock and postpone the thermal equilibrium time of the surrounding rock temperature field. For instance, considering ventilation for 361 days, with thermal conductivity increasing from 1 W/(m\(\cdot\)K) to 3 W/(m\(\cdot\)K), the cooling range of the surrounding rock temperature field (temperature drop value \(>0.01\%\) of the original temperature range) was 5.5 \(R\), 6.5 \(R\), and 7 \(R\), respectively. This is attributed to higher thermal conductivity leading to faster heat transfer within the surrounding rock, resulting in a more extensive range of disturbed surrounding rock under the same ventilation time. Figure 6 illustrates the time distribution curve of the dimensionless temperature of the roadway-surrounding rock under varying thermal conductivity. It is evident that, with the increase in dimensionless time under the same thermal conductivity, the dimensionless temperature gradually decreases, and the temperature drop rate also gradually decreases, ultimately reaching a constant value. Simultaneously, with an increase in thermal conductivity, the temperature drop rate of the surrounding rock gradually decreases, and the dimensionless temperature increases after stabilization. For example, considering \(R=0\), the dimensionless temperatures after stabilization are 0.04, 0.07, and 0.09. Compared with the VRT, the surrounding rock temperature decreased by 98%, 96.5%, and 95.5%, respectively. Additionally, the figure indicates that the influence of thermal conductivity on the temperature field of the surrounding rock gradually diminishes with an increase in dimensionless radius. As an illustration, considering \(Fo=2\), with an increase in thermal conductivity, the dimensionless temperatures corresponding to different dimensionless radii decrease as follows: \(R=0\): 95%, 90%, 83%; \(R=1\): 33%, 30%, 27%; \(R=2\): 11%, 10%, 9%; \(R=3\): 2%, 2%, 2%, respectively.