土石混合体细观结构及力学特性数值模拟研究  

MESOSTRUCTURAL CHARACTER AND NUMERICAL SIMULATION OF MECHANICAL PROPERTIES OF SOIL-ROCK MIXTURES

作　　者：徐文杰[1] 胡瑞林[1] 岳中琦[2] 谭儒蛟[1] 

机构地区：[1]中国科学院工程地质力学重点实验室,北京100029 [2]香港大学土木工程系

出　　处：《岩石力学与工程学报》2007年第2期300-311,共12页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家重点基础研究发展规划(973)项目(2002CB412702);中国科学院知识创新工程项目(KZCX3–SW–134)

摘　　要：土石混合体是一种非常复杂的不连续介质。随着数字图像处理理论的飞速发展,数字图像处理技术已经成功地应用于多种学科领域。通过利用数字图像处理技术建立土石混合体细观结构“概念模型”,并对其内部块体分布的结构特征进行统计分析研究,研究结果表明土石混合体的“混乱”状态只是其外在表现,其内部块体的分布具有良好的统计自相似性特点。利用几何矢量转换技术,将二元数字图像下土石混合体的概念模型转换为有限元软件可以接受的矢量格式,从而为土石混合体细观结构数值模拟提供基础。土石混合体大尺度直接剪切试验的数值模拟结果表明,土石混合体中的块石对其内部应力场具有明显的影响,从而影响了其相应的变形破坏形式。提出了内部塑性区扩展可能存在的3种模式。　Soil-rock mixture is a kind of inhomogeneous material;for the difficulty of in-situ sampling and the underdevelopment of large-scale laboratory soil test,at present the study of the soil-rock mixture′s mechanical properties is still at initial stage.With the quick development of digital image processing method,digital image processing has been successfully used in many kinds of fields.Based on the digital image processing,the microstructural model of soil-rock mixture by taking into account the actual material inhomogeneity is constructed.The structural character of the distribution of blocks is studied statistically;and it is shown that the confusion is only the external performance of the soil-rock mixtures.In fact,soil-rock mixtures have a good character of self-comparability in statistics.Using geometry transformation,the model of soil-rock mixtures under dual digital image has been translated into a document format which can be received by finite element software.By this step,the numerical simulation of actual microstructures of soil-rock mixture is carried out.The numerical simulation of the large-scale direct shear test indicates that the blocks obviously influence the stress field of soil-rock mixtures,and then influence the deformation and fracture type.Three kinds of possible failure propagation routes in soil-rock mixtures are put forward.

关 键 词：岩土力学 土石混合体 数字图像处理 细观结构 数值模拟 直接剪切试验 

分 类 号：TU41[建筑科学—岩土工程]