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以扫描电子显微镜拍摄获取的粉土图片为研究对象,把数字图像处理技术引入土体的细观结构观察和定量分析中,求解土颗粒孔隙度、颗粒粒径及颗粒形状等微观颗粒组成参数,为建立颗粒流离散元细观模型提供物理参数。在此基础上,对土样的三轴试验进行模拟,并研究细观力学参数(包括:摩擦系数、平行连接强度及刚度比)对宏观性质的影响。研究表明:通过颗粒簇模型和颗粒排斥法可以实现土体微观颗粒形状和粒径组成模拟。所建立的颗粒流模型能够很好地拟合土体的应力-应变关系和模拟试验中的剪缩-剪胀现象;摩擦系数、平行连接强度和刚度比对土体的初始模量和残余强度的影响规律有所不同;通过监测孔隙率的变化,可以反映土体剪切带发展的过程。
Taking the silt pictures taken by scanning electron microscope as the research object, the digital image processing technology was introduced into the mesostructure observation and quantitative analysis of soil so as to solve the microscopic particle composition parameters such as the porosity, the particle size and the particle shape of the soil particles, In order to establish the particle flow discrete element meso-model to provide physical parameters. On this basis, the triaxial tests of soil samples were simulated and the effects of meso mechanics parameters (including friction coefficient, parallel connection strength and stiffness ratio) on the macroscopic properties were studied. The results show that the model of particle size and particle size can be simulated by particle cluster model and particle exclusion method. The established particle flow model can well fit the stress-strain relationship of soil and the shear-dilatancy phenomenon in the simulation experiment. The friction coefficient, parallel connection strength and stiffness ratio of soil particle’s initial modulus and residual strength The influence law is different; By monitoring the change of porosity, the process of soil shear zone development can be reflected.