Fracturing Design Method based on the Fractal Fracture Mechanics

点击翻译按钮获取中文摘要

1. The application of a microscopic strength distribution and the fracture process zone can enable representation of the rock fracture process from micro-to macro-scales under an applied load. From these considerations, we proposed a fracture process analysis based on the Fractal Fracture Mechanics. In this analysis, the microscopic strength is modeled by Weibull' s distribution function and the inelastic behavior in the fracture process zone by a strength softening curve. The proposed fracture process analysis was perfomed for various applied pressures to investigate the influence of an applied pressure waveform on dynamic fracture process in rock.2. From the results of the DT tests and crack path analysis, it was shown that the crack density and preferred orientation of the pre-existing microcracks affected the crack growth behavior. The difference between the activation energies of subcritical crack growth in rock are caused by the preferred orientation of the pre-existing microcracks.3. A micro focus X-ray CT system was used to visualize the 3-dimensional microstructure of a rock specimen used in the dynamic tension test based on the Hopkinson's effect. Numerous cracks that do not coalesce to form a single fracture plane were observed and the multi-crack growth predicted by the Fractal Fracture Mechanics is confirmed. Furthermore, microstructures of Bentnite-Quartz Mixtures and Fiber-Cement-Stabilized Soils were observed and discussed