Hydraulic fracturing model of a layered rock mass based on peridynamics

•A coupled hydromechanmical hydraulic fracturing model based on the peridynamics is proposed.•A parallel double-bond constitutive model reflecting the mechanical properties of pre-failure rock interfaces.•A contact-friction constitutive model based on PD to reflect the mechanical properties of post-failure rock interfaces.•The effects of stress difference, elastic modulus ratio, and interface dip angle on the propagation behavior of hydraulic fractures in a layered rock mass is studied. In this work, we proposed a hydraulic fracturing model for layered rock based on peridynamics and studied the mechanism of hydraulic fracturing in a layered rock mass, i.e., complex propagation behaviors at the interface such as crossing, kinking, bifurcation, and arrest. Furthermore, we explored the effects of stress difference, elastic modulus ratio, and interface dip angle on the propagation behavior of hydraulic fractures. We found that the stress difference has an important influence on the propagation of hydraulic fractures in a layered rock mass. When the hydraulic fracture design direction is perpendicular to the direction of the maximum principal stress in a layered rock mass, the fracture network will be induced.