黏土微结构各向异性评估的谱系聚类方法  

Pedigree cluster method to evaluate geometrical anisotropy of soil micro-structure

作　　者：李顺群[1,2,3] 郑刚[1] 崔春义[4] 刘双菊[2,3] 

机构地区：[1]天津大学建筑工程学院,天津300072 [2]天津城市建设学院土木工程系,天津300384 [3]天津市软土特性与工程环境重点实验室,天津300384 [4]大连海事大学道路与桥梁研究所,辽宁大连116026

出　　处：《岩土工程学报》2010年第1期109-114,共6页Chinese Journal of Geotechnical Engineering

基　　金：中国博士后科学基金资助项目(20080430091);中国博士后科学基金特别资助项目(200902276);天津市高等学校科技发展基金计划项目(20071005)

摘　　要：由谱系聚类原理,给出了基于各种欧氏距离,即最长距离、最短距离、类平均距离和重心距离的微结构参数间的距离递推公式和微结构参数聚类过程,建立了黏土微结构几何属性的聚类方法。为了评估微结构参数几何各向异性的显著性,给出了各向异性系数的定义。对取自成层地基的某一样品进行了研究,其水平截面、竖直截面和45o截面上的SEM照片二值化参数分析结果表明,根据类平均距离法和重心距离法计算得到的各向异性系数非常接近,因此能很好反映自然固结成层地基的几何各向异性。另外,谱系聚类方法的分析结果与主成分分析方法的分析结果完全一致,这进一步说明,成层地基的几何各向异性是显著的。Respectively for each type of Euclidean distance, namely the maximum distance, the minimum distance, the average distance and the centrobaric distance, recursion formulae of distance between micro-structure parameters are deduced based on the pedigree cluster principle. Afterward, pedigree cluster method and corresponding process for clay micro-structure parameters are put forward to classify geometrical characters, and anisotropy coefficient is defined to evaluate significance of geometrical anisotropy. Studies on some SEM photos, taken in horizontal, vertical and 45° inclined planes from a layered soil sample, show that the anisotropy coefficient calculated by the average distance method is almost the same as that by the centrobaric distance method. In addition, the conclusion drawn by the pedigree cluster method is consistent with that by the principal component analysis method, and it illustrates that the geometrical anisotropy of the layered soil is distinct.

关 键 词：土微结构 几何各向异性 谱系聚类 类间距离 类内距离 

分 类 号：TU411.92[建筑科学—岩土工程]