Macro And Micro Analysis Of Shear Mechanical Properties Of Rock Mass With Regular Fractures And Slope Simulation Based On PFC

In nature,the existence of rock cracks is relatively common,because of the non connected,heterogeneous and anisotropic cracks in all kinds of rock engineering,the overall stability of rock mass is affected to varying degrees,and the strength,failure mode and crack propagation form of fractured rock mass under the influence of different forces will cause the failure of rock mass in geotechnical engineering It may even cause the collapse of the project,causing huge loss of life and property.With the development of hydropower station,mining and underground engineering,the scale of rock engineering involved is also expanding,so it is more urgent to study the mechanical properties and failure mechanism of fractured rock mass.In this paper,the model of fractured rock mass and fractured slope is cast by similar materials.Through the combination of experiments and PFC numerical simulation analysis,the following main research work is completed in this paper(1)In this paper,non through fractured rock mass specimens are poured with similar materials.Direct shear tests are carried out under four normal stresses(3MPa,4.5MPa,6MPa,7.5MPa).The effects of fracture length,fracture location and normal stress on the peak strength and shear parameters of fractured rock mass specimens are analyzed.The specimens with different fracture combination types are also discussed when the fracture length is the same The influence of the crack combination on the peak shear strength and shear parameters of the specimen is analyzed.(2)The direct shear tests of cross fractured rock mass specimens with different main fracture lengths were carried out by using similar materials.The direct shear tests were carried out under four normal stresses(3MPa,4.5MPa,6MPa,7.5MPa).The effects of main fracture length,main fracture angle and secondary fracture angle on the peak shear strength and shear parameters of cross fractured rock mass specimens were analyzed.(3)The PFC discrete element program is used to construct the samples of non through fractured rock mass,cross fractured rock mass,two non intersecting fractured rock mass and two groups of cross fractured rock mass for direct shear test.The numerical simulation results are co MPared with the physical test results.In addition,the macro mechanical properties of fractured rock mass with the change of fracture length,main fracture angle,secondary fracture angle and normal stress,the crack propagation mode in the failure process and the change of crack development mathematical model are analyzed.(4)The model of fractured slope is poured with similar materials,and the static loading test is carried out to analyze the influence of fracture length and fracture angle on the failure mode of slope.And the PFC discrete element program is used to build the slope model with cracks for simulation.The influence of single non through crack,two non through cracks and cross cracks on the failure mode of the slope model is analyzed.The crack propagation and block sliding displacement characteristics of the slope are mainly analyzed,so as to further verify and supplement the test results.