| The destruction of the fractured rock, the law of crack extension and strength analysis process in geotechnical engineering is an important area of research. In the interaction of cracks, propagation and coalescence in rock under the outside force action lead to many engineering accidents, Although many scholars with theory and numerical simulation, field test and experience obtained in fractured rock problem to do a lot of research, but the work also has disadvantages. So the fractured rock mass under the action of external force analysis of the failure process, the law of crack propagation and strength is particularly important. In this paper, using RFPA numerical software of fractured rock mass failure process were studied, the results for the tunnel excavation roadway supporting and underground to provide certain reference.And study the following conclusions:(1)Under uniaxial compression, the fracture of rock damage by the crack length, crack Angle,the crack surface friction coefficient and the distance from the rock boundary.The strength of the fractured rock mass and decreases as the crack length, with the increase of fracture Angle increase with the decrease of the first, when the fissure Angle45°to minimum, increases with the increase of the crack surface friction coefficient, along with the fracture increases with the increase of the distance from boundary.(2) The number of cracks, fissures fracture spacing and cross the geometric distribution will have a certain influence on rock strength. For parallel crack rock strength will increase as the number of cracks decreases with the increase of fracture spacing contain; for cross-fractured rock containing the intensity will be affected by the angle between the primary and secondary fractures, and most cross-fractured rock strength are higher than the intensity containing fractured rock mass containing a single.(3) More fractured rock mass damage process of a single fractured rock mass destruction is more complicated, its failure process including tensile failure and shear failure and shear failure of the composite; Increase in the number of cracks, the stress strain curve falling number will increase, this is because the fracture of rock bridge between lap, penetration and the slip crack surface influence. (4) Cracks will affect the destruction and the stability of surrounding rock of roadway. Roadway damage fracture angle is different, different form, and the surrounding rock displacement varies with the crack Angle. |
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