## 6 Conclusions  
(1) The deformation of the surrounding rock is most noticeable at the top and bottom of the roadway, and relatively less so at the footings. This is because the surrounding rock at the top and bottom experiences a more severe stress concentration, while the deformation at the footings may be smaller due to more uniform stress distribution or structural support. (2) As pore water pressure increases, the deformation of the surrounding rock also increases. When the pore water pressure is below a critical value, the increase in deformation is relatively small, but once it exceeds this value, the deformation sharply increases. This may be due to the water pressure beginning to exceed the rock's compressive strength, leading to partial or total instability in the rock structure. (3) The relationship between roadway burial depth and surrounding rock deformation is positively correlated, but this correlation is not absolute and is subject to specific conditions. At shallower depths, the height of the roadway has a more significant impact on rock deformation than its width, possibly because a taller roadway allows more vertical space for deformation. However, as burial depth increases, the impact of height and width on deformation tends to converge, likely related to the composite stress state of the deeper surrounding rock. As the rock grade decreases (becomes softer), the deformation trend of the rock mass significantly increases. (4) The multivariate regression prediction model for surrounding rock deformation derived from numerical simulations has higher accuracy than existing empirical statistical methods. This paper considers the effect of seepage and further analyzes the extent of impact of various factors on surrounding rock deformation, making it more suitable for predicting deformations in actual situations. A grey relational analysis was conducted on the factors, with the order of correlation magnitude being pore water pressure > roadway burial depth > surrounding rock classification > roadway height > roadway width. Although roadway height significantly impacts surrounding rock deformation, its correlation is relatively low because the influence of roadway height is revealed only in interaction with other factors, such as roadway burial depth. Analyzing roadway height alone does not reveal its impact in practical applications. (5) However, despite providing useful insights, this study has some limitations and drawbacks that need to be addressed in future research: 1 All data of the in this study were obtained through numerical simulations, which may lead to results that deviate from actual engineering situations. Although simulations can provide preliminary theoretical analysis and predictions, the heterogeneity of actual rocks, complex geological conditions, and real-world operational practices may significantly affect the accuracy of the simulation results. 2 The study did not take into account the support structures of the roadways, which are inevitable in actual engineering applications. The presence of support structures  
Figure 11: Results of correlation analysis. significantly affects the stress state and deformation behavior of the surrounding rock, so future studies should include the evaluation of support effects to more comprehensively understand the stability of the surrounding rock after excavation. 3 Although multivariate nonlinear regression and grey relational analysis provide methods for understanding the relationships among variables, these techniques also have their limitations. Multivariate nonlinear regression depends on the setup of the model and may not capture all the complex interactions between variables completely. Grey relational analysis, while revealing correlations between variables, may lack depth in explaining the specific influences between them. 4 Fluid-solid coupling simulations still face challenges when dealing with complex geological environments and the behavior of rocks under hydraulic actions.