广东工业大学 岩土工程研究所,广东,广州,510006
刘勇健(1968–),女,副教授,博士,主要研究方向为岩土工程. E-mail: liu-yongjian@163.com
网络首发:2018-11-23,
纸质出版:2018
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刘勇健, 伍建胜, 谢治堃. 基于NMR和SEM的软土微观结构特征试验研究[J]. 广东工业大学学报, 2018, 35(6): 49-56.
Liu Yong-jian, Wu Jian-sheng, Xie Zhi-kun. Experiment Study on Microstructure of Soft Soil in Nansha District Based on NMR and SEM Test[J]. 2018, 35(6): 49-56.
刘勇健, 伍建胜, 谢治堃. 基于NMR和SEM的软土微观结构特征试验研究[J]. 广东工业大学学报, 2018, 35(6): 49-56. DOI: 10.12052/gdutxb.180065.
Liu Yong-jian, Wu Jian-sheng, Xie Zhi-kun. Experiment Study on Microstructure of Soft Soil in Nansha District Based on NMR and SEM Test[J]. 2018, 35(6): 49-56. DOI: 10.12052/gdutxb.180065.
软土的含水特性和微观结构是决定其物理力学性质的主要因素. 以南沙软土为研究对象
运用核磁共振和扫描电子显微镜两种微观结构试验方法
获取了软土的弛豫时间
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2
谱图和扫描电子显微镜图像
总结了两种软土(淤泥和淤泥质土)的水相分布和孔径分布规律. 研究表明
南沙软土的
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2
分布曲线呈双峰型
土中存在两种状态的水分
第一种状态水超过质量的99%
孔隙多、孔径小
孔径分布主要集中在0.1~20 μm的区间. 南沙软土常见的微观结构类型为絮状结构、蜂窝结构和凝块结构3类. 计算了平均孔隙半径、平均孔隙面积、面孔隙率、孔隙形状因子和孔隙分维数等微观结构参数. 最后
对比分析了两种测试方法和应用中需注意的几个问题.
The moisture characteristics and microstructure of soft soil are the key factors in determining the physical and mechanical properties of soil. The relaxation time
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2
spectra and scanning electron microscope images of soft soil from Nansha District were obtained by means of nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM). The water phase and pore size distribution of two types of soft soils were summarized based on SEM and NMR test results. The results show that the relaxation time
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2
distribution curve of Nansha soft soil is bimodal with two kinds of water in soil
the first state water being over 99% of the total water quality
and muck and mucky soil havi
ng many small pores mainly concentrated in the range of 0.1 μm to 20 μm. SEM images show that the three microstructure types of Nansha soft soil are in flocculent microstructure
honeycomb microstructure and clot microstructure. These methods also can calculate the microstructure parameters such as average pore radius
average pore area
surface porosity
pore shape factor and pore fractal dimension. The results of pore sizes obtained by the two methods are basically the same
but not completely consistent. Finally
the characteristics of the two methods and several issues in the application of SEM and NMR test are discussed.
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