Abstract:Aiming at the problem of traditional strength criteria not considering intermediate principal stress and shear dilation in the stability analysis of deep roadway surrounding rock, a rock elastoplastic analytical model considering shear dilation was established based on Druck er Prager (D-P) yield criterion. By introducing the intermediate principal stress coefficient (s) to quantify the three-dimensional stress state, and combining the non correlated flow rule to define the expansion coefficients of the plastic zone and the fracture zone, the stress-strain expressions and partition radius analytical solutions for the elastic zone, plastic residual zone, and fracture zone were derived. The SHAP (Shapley Additive exPlans) value method was used to quantitatively analyze the influence and nonlinear characteristics of 12 parameters, including the intermediate principal stress coefficient and dilatancy angle, on the plastic zone radius (Rp) and fracture zone radius (Rz). The results indicate that the influence of the intermediate principal stress coefficient on the partition radius is nonlinear, with stable effects in the range of 0.4-0.8; The shear dilation angle in the plastic zone mainly promotes the expansion of the plastic zone and inhibits the development of the fracture zone; The influence of the shear dilation angle of the rupture zone on the radius of the rupture zone is controlled by multiple coupled factors. SHAP analysis reveals that the friction angle, original rock stress, and excavation radius within the plastic zone are key parameters affecting the zone radius, and their importance is significantly higher than physical parameters such as elastic modulus and Poisson"s ratio. The research results provide a theoretical model considering the coupling of multiple physical fields for the stability analysis of surrounding rock in deep tunnels, and the SHAP method provides a new approach for sensitivity analysis of complex geotechnical engineering parameters.