土体冻融对水份迁移影响及微观研究  

EFFECTS OF FREEZING AND THAWING ON SOIL WATER MIGRATION AND MICROSCOPIC STUDY

作　　者：程卫星[1] 崔宏环[1] 马玉涛[1] 杨鑫[1] 

机构地区：[1]河北建筑工程学院,河北张家口075000

出　　处：《低温建筑技术》2017年第7期78-81,共4页Low Temperature Architecture Technology

基　　金：[基金项目]张家口季冻区高等级公路路基填土在反复冻融条件下工程性质改变及改良研究(1411055A);张家口季冻区高等级公路路基土的力学特性及微观机理研究(XB201701)

摘　　要：为研究冻融循环作用对土体水份迁移的影响,采用自行研制的装置进行单向冻融试验,测定并分析了冻融循环作用下土体中水分迁移变化,同时利用扫描电子显微镜(SEM)采集了不同冻融循环次数的微观图像。通过对比研究了冻结温度、冻前含水率、孔隙直径、颗粒直径及微观结构特征变化对水分迁移的影响。结果表明:(1)随着冻融循环次数的增加,土样中含水率变化规律为逐层降低-回升变为逐层降低-平稳,最后变为逐层降低;(2)随着冻融循环次数增加,孔隙直径组成发生改变,大直径孔隙减少,小直径孔隙增加。In order to study the effect of freeze-thaw cycle on soil water migration, the self-developed device is used to do the unidirectional freeze-thaw experiment, and the changes of the soil water migration under freeze-thaw cycle are measured＇ and analyzed. At the same time using scanning electron microscope （SEM） the microscopic image of the soil under different freeze-thaw cycles are collected. The freeze-thaw experiments are performed to investigate the effect of freezing temperature, pre-freezing moisture content, pore diameter, particle diameter and micro-structure on the water migration. The resuits show that ①With the increase of freeze-thaw cycles, the regular of moisture content in soil samples can reduce- back into reduce- smooth, finally reduce step by step; ②With the increase of freeze-thaw cycles, the pore diameter changes, the big diameter pores reduces, and the small pore diameter increases.

关 键 词：冻融循环 水分迁移 扫描电镜 微观研究 

分 类 号：TU475.2[建筑科学—结构工程]