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为分析胶结砂岩的力学响应和破坏机理,基于试验建立不同刚度比的三维颗粒流数值模型,验证数值模型的可行性,并分析不同胶结性状的砂岩力学响应,进一步说明胶结物质的重要作用及模型的适用性.分析颗粒接触刚度比和平行黏结刚度与颗粒接触刚度的比值变化时,砂岩的应力比、体应变、配位数和平行黏结破坏数的变化规律以及对模型的泊松比、初始刚度和延性的影响.结果表明:不同的颗粒刚度比对岩样宏观力学响应的影响不同,颗粒接触刚度比越小,且切向刚度越大时,胶结砂岩的脆性越强;平行黏结刚度与颗粒接触刚度的比值越大,脆性越强,黏结破坏越容易,剪切破坏越明显.颗粒刚度对胶结砂岩的力学响应和变形能力有重要的影响,是实际储层砂岩力学模拟选择有效细观参数和构建本构关系的关键.
In order to analyze mechanics response and failure mechanism of cemented sandstone, three-dimensional particle flow numerical model with different stiffness ratios was established based on experiments to verify the feasibility of the numerical model and to analyze the mechanical response of sandstone with different cementation characters, and to further explain the important role of cemented material and model The relationship between the ratio of particle contact stiffness and the ratio of parallel bond stiffness to particle contact stiffness, the change law of stress ratio, volumetric strain, coordination number and parallel bond failure of sandstone, Stiffness and ductility.The results show that the influence of different particle stiffness ratio on the macroscopic mechanical response is different, the smaller the particle contact stiffness ratio is, and the greater the tangential stiffness is, the stronger the brittleness of cemented sandstone is. The parallel bond stiffness and The greater the ratio of particle contact stiffness, the more brittle, the easier the bond damage, the more obvious the shear damage.The particle stiffness has an important influence on the mechanical response and deformation capacity of the cemented sandstone, Parameters and the key to constructing constitutive relations.