Numerical Simulation Of Cracks Expansion Mechanism Of Rock

The seepage problem about rocks has been concentrated during the past years. As anatural geologic body, the formation of rocks includes some complicated courses. Thesecourses could make rocks generate many faults, which including apertures, fractures,joints and other discrete planes. Because of these faults existing, some conclusionswhich come from traditional continuum method could not well match the practicalphenomenon. So the researches of initiation, expansion and cut through of cracks in rockare especially important.The PFC2D software is used to simulate the expansion of cracks in rock based on theparticle flow theory with discrete element method. Under some dissimilar loading,expansion and evolution of a single crack with different dip angle and two cracks withdifferent arrangement have been discussed considering the different water pressure andside pressure.The main conclusions from above are as followed:1. Comparing with biax experiments processing in PFC2Dand experimentsprocessing in laboratory, the relationship between micro-physical mechanicalparameters and macro-mechanical response has been analyzed and established;2. The evolution of a single crack extended in the rock is simulated undermicroscope. The influences from different water pressure and side pressure have beenanalyzed for a single crack with different dip angle. The results show that the initialexpansion angle of the single crack increasing with side pressure, while decreasing withwater pressure;3. The effects of different water pressure which acted on rock with two cracks hasbeen analyzed. The results induce that with the same geometric position and otherloading, more wing shape cracks are formed with water pressure increasing. During thecracks expansion, less secondary shearing cracks formed, and the penetrating fashionwould changing from shearing failure to tension.