摘要
粉土在中国广泛分布,粉土液化现象的发生与粉土微观结构息息相关。将粉土的宏观抗液化特性与微观结构特征结合起来,分析了不同黏粒含量粉土微观结构的变化规律。利用扫描电子显微镜(SEM)获取不同黏粒含量粉土的微观结构图像并运用Image-Pro Plus(IPP)图像处理软件对粉土微观参数进行计算和分析。结果表明,随着黏粒含量逐渐增加,粉土内部结构逐渐紧密,颗粒接触方式由直接线或面接触转变为点接触,孔隙类型由架空孔隙向镶嵌孔隙转变;孔隙面积随孔径增大而增大,微、小和中孔隙的数量随黏粒含量的增加先增大后减少;随着黏粒含量的增加,微、小和中孔隙形态基本保持不变,但大孔隙的丰度和分形维数显著增加,结构的复杂程度增加。通过不同黏粒含量微观结构的变化规律,揭示了黏粒含量对粉土微观结构的影响以及粉土宏观抗液化特性的微观机制。
The silt is widely distributed in China and the occurrence of liquefaction is closely related to its microstructure.The macroscopic liquefaction characteristics and microstructural characteristics of the silt are combined to analyze the change of the microstructure of the silt with different clay contents.The microstructural images under different clay contents are obtained by the scanning electron microscope(SEM),and the Plus Image-Pro(IPP)image processing software is used to calculate and analyze the micro parameters of the silt.The results show that the interior structure of the silt becomes close with the gradually increasing clay content.The contact of particles transforms from the direct line or surface transformation into the point contact,and for the pore space types the overhead pore becomes the mosaic one.The pore area increases with the increase of its radius,and the number of micro,small and medium pores increases at first and decreases with the increase of clay particle content.The morphology of the micro,small and medium pores is essentially the same,but the abundance and fractal dimension of macropores increase significantly,and the complexity of the structure increases.Through change of the microstructure of the silt with different clay contents,the influences of clay content on its microstructure and micro mechanism of the macro liquefaction characteristics are revealed.
作者
黄春霞
黄敏
蔡伟
陈国兴
刘畅
张艳美
HUANG Chun-xia;HUANG Min;CAI Wei;CHEN Guo-xing;LIU Chang;ZHANG Yan-mei(College of Transportation Science&Engineering,Nanjing Tech University,Nanjing 210009,China;Nanjing City Vocational College,Nanjing 210092,China;College of Pipeline and Civil Engineering,China University of Petroleum,Qingdao 266580,China)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2020年第4期758-764,共7页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金项目(51478221,51108235,51208510)。
关键词
粉土
扫描电子显微镜试验
微观结构
黏粒含量
抗液化特性
silt
scanning electron microscope test
microstructure
clay content
liquefaction resistance
作者简介
黄春霞(1974-),女,博士,副教授,主要从事土动力学研究。E-mail:chunxiahuang@njtech.edu.cn。
