Peridynamics simulation method and application of hydro-mechanical coupling in fractured rock masses under dynamic disturbance

The hydro-mechanical coupling failure mechanism of fractured rock masses under dynamic disturbance remains a significant challenge in the field of rock mechanics. To address this, a peridynamics-based simulation method is developed to scientifically characterise the water pressure variations within water-bearing fractures subjected to dynamic disturbance and the associated rock mass damage. First, a governing equation for fracture seepage in the peridynamics framework is proposed. Building on this, a three-dimensional hydro-mechanical coupled peridynamics model for fractured rock masses is established, based on the principle of effective stress. Next, the response characteristics of fracture water pressure under dynamic disturbance (e.g., blasting impact) are analysed, and a mathematical expression describing the relationship between fracture deformation and water pressure variation is formulated. A three-dimensional peridynamics simulation method is then constructed to capture the coupled stress–seepage behaviour of fractured rock masses under dynamic loading. The evolution of water pressure and the dynamic propagation mechanisms of water-bearing fractures are subsequently investigated. The accuracy of the proposed method is validated through a series of numerical examples. Finally, the method is utilised to assess the stability of the surrounding rock during subsea tunnel construction using the drilling–blasting method. The influence of dynamic disturbance on tunnel stability is revealed, offering valuable insights for the safe construction of subsea tunnels.