铁道标准设计2017，Vol.61Issue(10)：48-52,5.DOI:10.13238/j.issn.1004-2954.2017.10.011
反复冻融作用下粉质黏土的微观分形特征研究
Study on the Microcosmic Fractal Characteristics of Silty Clay Subject to Repeated Freezing and Thawing
摘要
Abstract
Silty clay is often used in roadbed stuffing.The influence of freezing-thawing cycles on the microstructure leads directly to the change of subgrade strength.For the silty clay in north-eastern regions,the scanning electron microscope (SEM),mercury intrusion porosimetry (MIP) and unconfined compressive strength tests after freeze-thaw cycling are conducted.Based on fractal theory,threedimensional fractal dimensions of soil particle and pore are calculated,and the relation formula between fractal dimensions and mechanical strength is created.The results indicate that with the increase of freezing and thawing cycles,soil is rearranged and its integrity is destroyed.Meanwhile,the pore volume tends to fluctuate and increase.With the increase of the water content,the pore content of pore size in 5 ～20 μm gradually decreases,while,that of pore size in 0.3 ～ 5 pm increases.In the progress of freeze-thaw cycling,the changing characteristics of soil microstructure are well reflected by fractal dimension.The egression equations constructed by fractal dimension and unconfined compressive strength show that the bigger the fractal dimension,the higher the strength.关键词
粉质黏土/冻融循环/分形维数/扫描电镜/压汞实验/无侧限抗压强度Key words
Silty clay/Freeze-thaw cycle/Fractal dimension/Scanning electron microscope/Mercury intrusion porosimetry/Unconfined compressive strength分类
交通工程引用本文复制引用
李楠,王天亮,徐昌,吴泽,王海航,程博远..反复冻融作用下粉质黏土的微观分形特征研究[J].铁道标准设计,2017,61(10):48-52,5.基金项目
河北省自然科学基金项目(E2013210040) （E2013210040）
