辽西黄土湿陷变形特性及湿陷后微观结构变化  

Collapsible Deformation Characteristics and Its Changes in Microstructure of Loess in West of Liaoning

作　　者：王常明[1] 林容[1] 陈多才[1] 张先伟[1] 王科[1] 

机构地区：[1]吉林大学建设工程学院.长春130026

出　　处：《吉林大学学报（地球科学版）》2011年第2期471-477,共7页Journal of Jilin University：Earth Science Edition

基　　金：国家自然科学基金项目(40972171);吉林大学种子基金项目(40870433)

摘　　要：初始含水率对黄土湿陷性具有重要的影响。利用人工制备不同含水率的试样对辽西黄土的湿陷变形特性进行了试验研究,并采用SEM技术测试了黄土湿陷前后的微观结构变化,采用微结构定量化分析方法和分形几何方法分析了黄土试样微观孔隙的变化特征。结果表明:1)初始含水率对辽西黄土的湿陷变形具有显著的影响,随着试样初始含水率的增大,同一压力下的湿陷变形量越来越小;2)不同初始含水率试样的压力-变形关系曲线可以统一用双曲线形式表达;3)湿陷后黄土试样的结构变得较为致密,孔隙总数显著增加,而孔隙面积减小。湿陷过程主要是小孔隙数量增加、孔隙形状分维数减小、孔隙复杂程度显著增加的过程。The initial moisture content has important influences in collapsibility of loess.The collapsible deformation characteristics is studied in laboratory under a set of man-made samples with different moisture contents.And the microstructure of the samples are tested by using SEM technique,furthermore the microstructure of samples is analyzed by the quantitative method and fractal theory.The results are shown in the followings as：1）the initial moisture content obviously effects the collapsible deformation of loess in west of Liaoning.The collapsible deformation increases with the initial moisture content and increment of collapsible deformation is getting small under a certain pressure.2）The relation between vertical stress and vertical strain for samples with different moisture contents can be all described by a hyperbola function.3）The microstructure of loess samples is getting dense,the average number of pore of samples obviously increases and the pore area decreases after the sample is collapsed.The collapse is a process that small pore increases,fractal dimension decreases,and complexity of the pore increases.

关 键 词：湿陷变形 孔隙形状分维数 孔隙定量分析 微观结构 

分 类 号：TU443[建筑科学—岩土工程]