三维重构下整体形状参数的砂土渗透性分析

Permeability analysis of sand with overall shape parameters under 3D reconstruction

为探究颗粒形状对砂土结构及渗透性的影响规律,选取玻璃珠、石英砂及玻璃渣3种颗粒形状各异的砂土采用高分辨率三维X射线显微镜进行精细扫描,重构砂土三维结构模型;选取颗粒伸长率、扁度、球度、孔隙比表面积等形状参数,统计分析得出整体形状参数;将整体形状参数引入科泽尼-卡尔曼方程方程,得出考虑颗粒形状特征的砂土渗透系数的预测方程.室内柔性壁渗透试验表明,砂土颗粒的整体形状参数越小,即颗粒形状越复杂,砂土的渗透性能越差,引入整体形状参数的科泽尼-卡尔曼方程方程对砂土渗透性能的预测效果较好.

In order to explore the influence of particle shape on the structure and permeability of sand,three kinds of sand with different particle shapes,glass beads,quartz sand and glass slag,were selected as the research objects.First,high-resolution three-dimensional X-ray microscope was used for fine scanning,and the three-dimensional structure model of sand was reconstructed.The shape parameters such as particle elongation,flatness,sphericity and pore specific surface area are selected for statistical analysis to obtain the overall shape parameters,and the overall shape parameter is introduced into Kozeny-Carman equation to obtain the prediction equation of sand permeability coefficient considering particle shape characteristics.The indoor flexible wall permeability test shows that the smaller the overall shape parameter of sand particles,that is,the more complex the particle shape,the worse the permeability of sand.The Kozeny-Carman equation introducing the overall shape parameter has a better prediction effect on the permeability of sand.