Peridynamics simulation of hydraulic fracturing in three-dimensional fractured rock mass

Fissures in rock masses offer sites for groundwater seepage and weaken the mechanical properties of rocks to a certain extent. Moreover, seepage water pressure exerts a direct influence on engineering construction and may even trigger engineering accidents. For three-dimensional fractured rock masses, the MATLAB program was independently programed based on the Monte Carlo method to build a three-dimensional fracture network model of the natural rock mass, realize visual reconstruction of three-dimensional fractures, and generate a three-dimensional fractured rock mass model based on the statistical data of fractures in the literature. Using the established three-dimensional fluid–structure coupling simulation method, the simulation of prefabricated directional hydraulic fracturing and the hydraulic fracture propagation law of naturally fractured rock masses with different inclination angles are performed. The results highlight several complex mechanical behaviors, such as shear and tension, in the hydraulic fracturing process of the fractured rock mass. The expansion mode of hydraulic fracture is mainly controlled by two factors: propagation induced by natural fractures and propagation controlled by the maximum principal stress. Therefore, establishing a three-dimensional fractured rock mass fluid–solid coupling peridynamics simulation method can provide an effective means of analyzing the damage and failure process of fractured rock masses under the stress-seepage coupling effect.