Study On Simulation Method And Method Of Determining Destruction Process Of Jointed Rock Mass

As a kind of common engineering medium, rock mass media widely distributed in water conservancy and hydropower, transportation and mining and other fields. its engineering mechanical properties such as strength and deformation directly related to the economic and security projects.Rock mass is the product of long-term geological tectonic movement, contains a large number of discontinuous surface structure, such as:fault, joint, bedding, fissure, etc. These structural planes are cross-cut each other to form a specific rock structure, then, the complex structure characteristics determine the failure mechanism and engineering mechanical properties of strength and deformation of the rock mass. A large number of engineering practice showed that the deformation, destruction and instability of the rock mass is usually caused by the deformation, damage, expansion and even through of its internal structure surfaces. Therefore, first of all, to study the engineering mechanical properties such as strength and deformation of the joint rock mass, we should to understand the deformation, destruction, extension, even to through of the jointed structure plane in the rock mass.To the characteristics such as failure process and strength, deformation of the joint rock mass, paper on the basis of the indoor direct shear test of the rock mass that has a typical structure study the deformation, destruction, expand the evolution process of the rock mass; introducing the basic concepts of fracture mechanics to realize the simulation of the deformation, destruction, expand the evolution process of the rock mass by using the numerical manifold method; on the basis of before, doing research to ensure the engineering mechanics parameters of the joint rock mass by doing numerical simulation experiment. The main research work includes the following several aspects.(1) At the basis of making a typical mold device of jointed rock mass and optimization test detection system, designing the overall scheme of the test. Carrying out the indoor direct shear test on the deformation, destruction, expand the evolution process of joint and rock bridge joint of the rock mass, getting the experimental data and image data on the damage evolution of the seven kinds of model of rock under the condition of shear load. The before job provides the original test data for the simulation of the deformation, destruction, expand the evolution process and research of strength and deformation characteristics of the rock mass.(2)After studying the seven kinds of model of rock and 35 the stress-strain curves, the stress-strain curves are divided into five types:Sliding type, yield type, cut type, brittle fracture type, cut complex, and giving characteristics and judgment on each kind of stress-strain curve type. Experimental results show that the structural plane form and the normal stress of rock mass decide the stress-strain curve type. Along with the rising of the method to the stress, shearing type into cut complex type, cut complex into yield type.(3)Do the assessment of the program of the numerical manifold method. The result shows that when changing the matrix inertia and gravity field, In the process of numerical manifold method, it will ignore the "conservation of mass". In this article, it will fix cell density to realize the "conservation of mass" in the process of calculation, improving the calculation accuracy. On the basis of the two-dimensional block search of the expression of matrix put forward the virtual joint technology, ensure that the joint distribution doesn’t change length in the process of block search, and also develop the process of the automatic generation of numerical sample.(4)Build the expression of matrix of the three-dimensional block search by the formula of vector operation of the 3D geometric information judgment, achieve a three-dimensional geometry of arbitrary block search. Lay the foundations for the research on three-dimensional joint rock mass, has carried on the preliminary exploration for future research.(5)On the basis of the basic concept of fracture mechanics stress intensity factor, calculate the crack tip stress intensity factor by using the Contour integral method and ensure the criterion and the direction of the joint extension by the rule of maximum axial force. This aspect solves the mathematics unit, the reconstruction of physical unit and the stress transfer in the process of the jointed rock mass destruction, and also develop the process of the simulation of the deformation, destruction, expand the evolution process of the rock mass, and then carry out the indoor direct shear test and uniaxial compression test, Brazil disc test on the deformation, destruction, expand the evolution process of joint and rock bridge joint of the rock mass to verify this simulation program. The verification results show that the result of the process of the simulation of the deformation, destruction, expand to the evolution process of the rock mass has good geometric consistency with the result of the test, so it can simulate the process of the simulation of the deformation, destruction, expand the evolution process of the rock mass.(6)After a large number of joint rock numerical simulation test, proposing the train of thought and method of that ensure the parameters of mechanical properties of the joint rock mass and study on the size effect, anisotropy parameters. Providing a scientific and effective technical means for the study on the engineering mechanical characteristics of jointed rock mass.