谭龙, 韦昌富, 田慧会, 王卉, 张芹. 2017: 土体持水特性及孔隙水分布特性的试验研究. 工程地质学报, 25(1): 73-79. DOI: 10.13544/j.cnki.jeg.2017.01.010
    引用本文: 谭龙, 韦昌富, 田慧会, 王卉, 张芹. 2017: 土体持水特性及孔隙水分布特性的试验研究. 工程地质学报, 25(1): 73-79. DOI: 10.13544/j.cnki.jeg.2017.01.010
    TAN Long, WEI Changfu, TIAN Huihui, WANG Hui, ZHANG Qin. 2017: EXPERIMENTAL STUDY ON CHARACTERISTICS OF PORE WATER DISTRIBUTION AND WATER-HOLDING CAPACITY OF SOIL. JOURNAL OF ENGINEERING GEOLOGY, 25(1): 73-79. DOI: 10.13544/j.cnki.jeg.2017.01.010
    Citation: TAN Long, WEI Changfu, TIAN Huihui, WANG Hui, ZHANG Qin. 2017: EXPERIMENTAL STUDY ON CHARACTERISTICS OF PORE WATER DISTRIBUTION AND WATER-HOLDING CAPACITY OF SOIL. JOURNAL OF ENGINEERING GEOLOGY, 25(1): 73-79. DOI: 10.13544/j.cnki.jeg.2017.01.010

    土体持水特性及孔隙水分布特性的试验研究

    EXPERIMENTAL STUDY ON CHARACTERISTICS OF PORE WATER DISTRIBUTION AND WATER-HOLDING CAPACITY OF SOIL

    • 摘要: 采用轴平移技术对砂土、粉质黏土、黏土3种土质的土-水特征曲线进行了测试分析,并结合核磁共振技术测得了试样在不同基质吸力加载步条件下的T2时间(横向弛豫时间)分布曲线,从细微观角度分析了脱湿过程中孔隙水在土体中赋存分布的情况。实验结果表明:3种土质的体积含水率随着控制吸力的增大而减少,该脱湿曲线可分为边界效应区、过渡区与残余区3个区域。其中,黏土的持水特性明显大于粉质黏土和砂土。核磁共振的试验结果与压力板仪获得的脱湿过程是对应的,从微细观角度展示了土体的排水过程。在排水过程中,总体上具有较大势能的大孔隙水先排出,随后小孔隙开始排水,但这一规律并不绝对,由于土体孔隙结构的复杂性,会出现大小孔隙同时排水以及土样中水分重分布的现象。

       

      Abstract: The soil water characteristic curves of sand, silty clay and clay are measured by axis translation technique. The T2 distribution curve of specimens are tested under different matric suction loading steps combining with nuclear magnetic resonance(NMR) technique. The distribution of pore water in soil is discussed with the T2 distribution curve from the microscopic point of view during drying process. The results show that volumetric water content gradually reduces with the increase of the suction. The drying curve can be divided into three sections:boundary effect zone, transition zone and residual zone. In addition, the clay water-holding capacity is obviously higher than that of silt and sand. The tests of NMR are corresponded with drying process in the pressure plate apparatus. The results of NMR tests further show the drainage process of soil from the microscopic of perspective. On the whole, the large pore water with large potential energy is discharged first in the drainage process of soil, and then the water in small pores begins to drain. However, this rule is not absolute, because of the complexity of the soil pore structure. There will be a phenomenon of simultaneous discharge of different size porosity of pore water and the redistribution of pore water in soil occurred during the drying process.

       

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