| Discontinuous jointed rock mass is the most common and most important geological body in rock mass engineering.The failure of rock masses with non-continuous joints is usually composed of joints and rock bridge failures,and the overall damage characteristics are the composite failure surfaces consisting of primary joints and rock bridge failure surfaces that extend from joint ends.Under external loads,cracks near the joint surface of the rock bridge will develop and propagate inside the rock bridge,resulting in weakened mechanical properties.The weakening of mechanical properties of rock bridges is essentially a mechanical process in which internal micro-elements of rock bridges are destroyed under external loads,micro cracks are formed inside the rock bridges,and micro cracks are gradually connected until they are destroyed.This article describes in detail the research on the theoretical,experimental and numerical simulations of non-through joint rock mass at home and abroad.Based on previous researches,this paper introduced the theoretical basis of particle flow software for discrete particle PFC?Particle Flow Code?,and established a meso-scale numerical model of rock mass with non-through joints using PFC2D5.0,and then cut it according to the indoor direct shear test.Curve and numerical simulation tests compare the cohesion and friction angles obtained by the shear curve and repeat the calibration to achieve the purpose of meso-scopic parameter calibration.According to the results of numerical simulation,the types and distributions of cracks in non-penetrative jointed rock mass under different working conditions,such as different joint connectivity,different joint angles and different normal stresses,can be obtained qualitatively and quantitatively,and the number of cracks with the shear displacement curve.Summarize the meso-mechanism of uninterrupted jointed rock mass expansion through different connection rates,different joint angles and different normal stress conditions. |
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