Simulation Of Hydraulic Fracturing Of Rock Mass Using Element-free Method

As the groundwork and environment of constructions in large scale projects, engineering rock mass is the geological structural mass composed of rock blocks and discontinuities. The propagation and perforation of near joints and cracks is the main destroy form, which caused by the impaction of the engineering disturbence and geological environment. In engineering rock mass, groundwater deposit in the cracks of rock mass. Its hydraulic pressure on the crack surfaces makes the intrinsic cracks or flaws appear propagation and perforation, which named by hydraulic fracturing. Hydraulic fracturing is one of the important influence factors of the stability of rock mass and the engineering buildings upon the rock mass in the rock engineerings with wicked hydro-geological conditions, such as high water pressure and deep burying.According to the analysis of hydraulic properties in cracks full of water, the form and characteristics of hydraulic pressure on the crack surfaces were studied in this paper. Then the influence on the stress field, strain field and displacement field in the area of crack tips and the consequent displacement of rock mass, as well as the propagation of crack fracturing were also studied. In this paper, combining with the theory of facture mechanics, study on the application of element-free method to simulate hydraulic fracturing was presented due to the advantage of using element-free method to simulate crack propagation. The stress intensity factor of complex fracture was calculated using the modified J integral and an element-free program for the simulation of hydraulic fracturing was complied.The simulation of hydraulic fracturing of rock mass using element-free method is just an attempt in numerical method in according with the advantage of using element-free method to simulate crack propagation. In the calculate deduction, theformula of crack tip's stress intensity factor in complex fracture condition was presented considering with the hydraulic pressure on crack surface and the gravity of rock mass. The element-free program tracing crack propagation in quasi-steady has a better description of the track of crack propagation. The simulation of hydraulic fracturing of multiple fracture geometry shows the interaction of parallel and subparallel fractures.