Study On The Numerical Simulation For The Propagation Process Of 3d Built-in Fractureand Of Rock

The 3D fracture development process and propagation mechanism of the rock material is an important research topic on the rock engineering fields and the fracture propagation result in some problems about unsteady or damage of rock engineering, but the present the research hasn't achieved breakthrough progress. Because using real rock we can't make the specimens to do the 3D fracture propagation test, which shows that the 3D fracture propagation law is difficult to obtain from the test. Therefore, it is necessary to do some research about the process of 3D fracture propagation through numerical simulation.In the first, the text introduces some classical fracture mechanics, stress of fracture and basic knowledge of numerical simulation software. On this basis, the propagation tests of 3D single crack and 3D double cracks under uniaxial compression are numerically simulated. Through numerical simulation the images and data of plastic zone variations, minimum stress variations, maximum stress variations and shear stress variations during the fracture propagation process are obtained. Initial propagation strength, length of self-similar crack propagation, wing crack propagation length and general rule of fracture propagation are obtained from analysis of the images and data. Numerical results show that self-similar propagation earlier than the propagation of wing crack. The failure of the specimens is caused by the propagation of wing crack. When the length of Rock Bridge equals to 4 times of the crack radius, the dual cracks propagation of dual cracks results in penetration of rock bridge, but the crack propagation in rock bridge areas isn't severe. The propagation law of dual cracks is mainly the same as that of single crack.Numerical experiments are provided for analyzing the propagation process of 3D built-in fracture, which reveals the basic laws in unstable failure process of rock. The achievements lead to a further cognition to the three-dimensional fracture problems and can also be applied to analyze the problems such as stability of rock and soil engineering structure. Therefore, it is of important theory value and practical significance.