Abstract: The current numerical methods for addressing multifield coupling issues during metro construction in water-rich areas have certain limitations. To better reflect the impact of stress-seepage-damage coupling on metro construction, control equations for the rock stress field and seepage field are provided based on the Hoek-Brown elastoplastic damage model from previous research, and permeability evolution equations for different rock states (elastic, plastic, and failure) are given. Then, an elastoplastic stress-seepage-damage coupling model based on the Hoek-Brown criterion is established, and a User-defined Material subroutine is developed for application of ABAQUS simulation calculation. Finally, the simulation results are compared with laboratory test to validate the applicability of the model, this can improve ABAQUS′s deficiencies in hydraulic-mechanical-damage coupling calculations. The model is applied to the construction process analysis of the Dalian metro line 5, which can effectively reflect the influence of groundwater on the stability of surrounding rock and support structures during metro construction.

Key words: metro tunnel, Hoek-Brown elastoplastic damage model, multifield coupling, seepage effect, numerical simulation