岩土工程学报2011，Vol.33Issue(12)：1919-1925,7.
冻融作用对压实黄土结构影响的微观定量研究
Quantitative analysis of impacts of freeze-thaw cycles upon microstructure of compacted loess
摘要
Abstract
After a series of laboratory experiments in an open system,the impacts of freeze-thaw cycles on the structure of compacted loess are studied by means of the quantitative analysis of scanning electron microscope images.The physical properties of the soils are tested simultaneously to discuss the relationship between microstructure and macro-properties of the loess.The results of microstructure analysis show that,with the increase of freeze-thaw cycles,the formation of cryogenesis results in obvious enlargement of pore volumes and therefore extrusion and redistribution of soil particles.The ratio of big-and mid-pore area to the total pore area increases from 78% after 2 cycles to 90% after 31 cycles.Meanwhile,some pores with open structure,which controls the loess collapsibility,are formed during the cycles.The results of macro-properties test show that,during the cycles,the water content of the samples increases significantly and is redistributed,and the dry density of the samples decreases initially and then keeps almost constant.After 31 cycles,the water contents at the upper and lower parts of the sample increase by more than 140% and 55%,respectively,whereas the dry density of the sample decreases from the initial value of 1.86 g/cm3 to 1.55 g/cm3,about a depression of 17%.Collectively,the results from both the micro-and macro-analyses indicate that the freeze-thaw action significantly weakens the structure of compacted loess.关键词
压实黄土/冻融循环/电镜/宏观和微观特性Key words
compacted loess/freeze-thaw cycle/scanning electron microscope/microscopic and macroscopic property分类
建筑与水利引用本文复制引用
穆彦虎,马巍,李国玉,毛云程..冻融作用对压实黄土结构影响的微观定量研究[J].岩土工程学报,2011,33(12):1919-1925,7.基金项目
国家自然科学基金项目 （）
西部交通建设科技项目 （）
中国科学院西部行动计划项目 （）
冻土工程国家重点实验室研究项目 （）
