Numerical study on rock fracturing with pulsed pressure in hard rocks with a pipe-domain seepage model

Abstract

The disintegration process and the fracture propagation degree in rock masses under pulsed pressure are of great interest to the engineering community. This study presents a novel numerical simulation method for pulsed pressure-induced rock fractures based on the stress analysis in the elastic medium and the use of the boundary conditions with internal and external pressures. To enclose the particles, a method of constructing pipe network is proposed via the particle flow code (PFC2D) method, which facilitated the control of fluid flow and pressure by incremental pressure. This method was rooted in the pipe domain percolation approach and allowed for the understanding of the loading process and crack propagation mechanism through the laboratory experiments and engineering cases. The results demonstrated that the fracturing of rock mass under impulsive loading was a combined effect of stress waves and high-pressure fluids. The action of the stress wave induced initial cracks in the rock masses, while the fluid penetrated into these cracks, exerting pressure on the surrounding particles. This led to an increase in fracture width and an influx of more fluid, which enhanced the fracturing process. The fracture lengths induced by the fluid splitting action accounted for over 60 % of the total. The method provides a solid foundation for analyzing the mechanisms of pulsed pressure-induced rock fracturing and offers invaluable insights into predicting the degree of disintegration.