Study on Temporal Changing Regulations and Evolution Model of Surrounding Rock Disturbance in Subway Tunnel

To deeply investigate the temporal changes of surrounding rock disturbance in the construction process of subway tunnel, the finite element numerical simulation was conducted to analyse the stress and strain changes induced by excavation, and the comparison of crown settlements at different excavation stages was performed, and then the displacement and stress state of surrounding rock during the excavation process was summarized. The evolution model for surrounding rock disturbance was proposed and validated by integrating wavelet analysis with the auto-regressive integrated moving average (ARIMA) model. The results indicate that: With tunnel excavation progresses, the stress distribution in the surrounding rock undergoes significant reorganization. Stress concentrations are particularly evident after initial support installation, especially following the completion of upper bench excavation. However, employing a stepwise excavation strategy with enlarged arch foot benches effectively reduces the scope of surrounding rock stress and stress concentration phenomena, thereby minimizing the impact of stress and strain changes on surrounding rock stability during excavation. Furthermore, the evolutionary model based on the W-ARIMA method successfully captures the overall dynamic changes of tunnel deformation. These findings can provide a new perspective and methodology for surrounding rock stability management in tunnel construction.