岩土二维真实细观数值分析方法研究

Numerical analysis research on the 2D actual meso-structures of soil

分析岩土细观应力特征,通过Ostu’s类判别法对水泥土初始状态细观图像进行二值化处理,经灰度形态学算子"腐蚀"、"闭合"运算,得到表征水泥土细观结构特征的二值图像.然后通过边缘检测,几何矢量化转换成有限元软件识别的矢量图,形成水泥土二维真实细观有限元模型.利用多孔弹性本构关系进行数值分析,结果表明:该研究揭示水泥土细观真实应力、变形的全场变化规律;定量分析水泥土的细观非线性力学特征,体现水泥土强度和变形的细观机理.

In order to analyze the stress property of soil meso-structures,the meso-image captured before loading on the cement-soil half-cylinder sample has been processed binarily using the Ostu＇s method. Then grey morphological operators such as ＂erosion＂and＂closing＂also have been performed on the binary image,the distribution structures about soil particles and voids that form the inhomogeneity of the geomaterial in the image are identified. By the edge detection,vector transform are used to acquire the vectorized digital image which is the input document for the finite element software. So,the soil actual meso-model is established by the Finite Element Method. Using the porous media theory,we carry out numerical simulation,and the results show： 1） based on the meso-numerical analysis, this research can reveal the actual meso stress and deformation distributions of soil. 2） the meso-nonlinear features of soil sample are studied quantitatively which embody the meso-mechanism of the strength and deformation about cement-soil.