Study On Deformation And Fracture-damage Mechanism Of Rock Based On The Spatial Correlation Characteristics

To make the established numerical model more in line with the real rock structure and improve the calculation accuracy of meso-mechanical model of heterogeneous rock,this article developed the method of spatial correlation by introducing the spatial correlation length and anisotropic parameters.Taking slate and granite as the main research objects,by using Matlab and particle flow software PFC^2D and combined with the meso-scopic parameter inversion technique,this article established a granular elements mechanical model that can characterize the different slate schistosity orientation and reflect the microstructure of granite respectively.The Brazilian splitting numerical simulation experiment was also carried out to study the anisotropy of slate and the damage behavior of weathered granite and its fracture mechanism.Based on the spatial correlation characteristic method,not only the actual meso-structure distribution characteristics of rock could be more truly reflected,but also the content of multiphase minerals and their mineral components in the rock itself can be considered,and the meso-mechanics model of different types of rock could be established conveniently and efficiently.Based on above method and particle flow software,the mechanics characteristics and deformation-rupture law of rock-like materials was well simulated,which showed good consistency with the experimental results.It also provided a new method for studying the deformation and fracture behavior of quasi-brittle materials such as rocks.The main research work and innovation achievements include:?1?From the perspective of spatial correlation,the spatial correlation length and anisotropy parameters were introduced to establish the numerical realization of the spatially correlated random field,and the represented results of its meso-scopic structure in different types of rocks were analyzed and discussed.?2?Taking the slate as the research object,numerical value of rock samples reflecting the meso-structure of the slate were established by determining the spatial correlation length and anisotropy parameters.Based on the meso-mechanical parameters obtained from the inversion,the Brazilian splitting numerical test was conducted,which proved the reliability of above model.Meanwhile,a slate fine-mesoscale elemental model that can characterize the different slate schistosity orientation was established.This paper also carried out numerical simulation analysis of the splitting-pull test for numerical rock samples with different schistosity orientation,and the anisotropy of stratified rock was studied.?3?Taking granite as an example,the microstructures of the weathered granite were analyzed by electron microscopy scanning and X-ray diffraction experiment.The Brazil splitting experiment was also conducted on the splitting tensile fracture response of the granite.Meanwhile,starting from the microscopic characteristics of rocks,the spatial correlation method was used to represent the characteristics of the meso-structural heterogeneity of the granite by establishing the granular elements numerical model.The Brazilian splitting test was simulated and analyzed.In addition,this article also studied the effect of loading rate on the fracture behavior of granite.The mechanism of deformation and failure of granite was revealed through experiments and numerical simulation.