Seepage-fracture coupling mechanism of rock masses cracking propagation under high hydraulic pressure and numerical verification

With the theory of fluid mechanics and fracturing mechanics combined with Monte Carlo method to describe random distribution of rock cracks, seepage-fracture coupling mechanism involving deformation of primary crack, initiation, propagation and coalescence of wing cracks under high hydraulic pressure was studied. The mathematical model of seepage-fracture coupling of rock masses cracks propagation was established. The solving strategies and methods were proposed, as well as developing the analysis program HWFSC. for for seepage-fracture coupling of cracks propagation under high hydraulic pressure on the Fortran95 platform. The fact that crack networks and seepage initial condition vary with seepage conditions embodies in seepage-fracture coupling of cracking propagation under high hydraulic pressure. Coupling analysis of the process of rock cracking propagation during high pressure water injection process comes to the conclusion: starting water pressure has been shown to reside in rock cracking propagation under high hydraulic pressure, when the water pressure is more than the starting water pressure, the wing crack is born on the crack tips, as water pressure on the crack tips increases, the wing cracks propagate, and then coalesce with other cracks, finally stop propagating. The analysis of seepage-fracture coupling considers the influence of the dynamic and static water pressure of the cracks on the cracks normal expansionary and the wing cracks propagation, and the number of connected cracks increases as the seepage develops. Analysis of seepage-fracture coupling analysis of rock cracks can re-create the phenomenon of hydraulic fracturing, describe the process of rock cracks propagation, the rock bridge coalescence and inter-coupling response of seepage in fractured rock masses.