Experiment And Particle Flow Simulation On Mechanical Properties Of Layered Composite Rock Under Uniaxial Compression

It’s widely distributed in nature with layered composite rock, since the long and complicated geological process of earth. This kind of rock mass is often composed of stratas with different lithologies, and have strong combinations between the layers. Anisotropic and discontinuity in layered composite rock mass are significant different from that with single lithology, Its mechanical characteristics are not only affected by structural plane, the mechanical properties of each layer and strata inclination dose equally, Therefore, we need more study on its mechanical characteristics and recognize its mechanism of deformation and failure. In this research, mechanical characteristics of layered composite rock-like specimen which made by rock-like materials, are investigated by uniaxial compression test and particle flow code numerical simulation. A major description can be drawn as follows.(1) A series of moulds for layered composite rock-like specimen making has been designed and processed, as same as the method for rock-like specimen drilling and processing, with different dip angle. Two rock-like materials have been obtained through a series proportioning test with cement, quartz sand and calcined gypsum. Major mechanical characteristics of onefold rock-like specimen, which made by aforesaid two rock-like materials respectively, have been investigated under conventional triaxial compression test and Brazilian test.(2) Layered composite rock-like specimen constituted by aforesaid two rock-like materials have been made, consist of three groups of layer thickness ratio, with dip angle varied from 0° to 90°. Strength and deformation characteristics, acoustic emission feature and failure mode have been investigated respectively under uniaxial compression, with acoustic emission(AE) data and process of crack propagation on the surface of the specimen obtained at the same time.(3) Simulation model of layered composite rock-like specimen has been constructed by assigning micro-parameters to different regions and importing joints in Particle Flow Code 2D(PFC2D). A group micro-parameters, which can reflect the result of actual test, has been obtained by a series debugging, based on sensitivity analysis of micro-parameter in PFC2D. Simulation results reflect the actual test appropriatly, deformation and failure mechanism in micro level have been analyzed in-depth, through crack number evolution and mesoscopic displacement field obtained in PFC2D.