张亚国, 梁伟, 郭松峰, 等. 2022. 黄土孔隙结构演化对其土-水特性影响分析[J]. 工程地质学报, 30(6): 1998-2005. doi: 10.13544/j.cnki.jeg.2022-0578.
    引用本文: 张亚国, 梁伟, 郭松峰, 等. 2022. 黄土孔隙结构演化对其土-水特性影响分析[J]. 工程地质学报, 30(6): 1998-2005. doi: 10.13544/j.cnki.jeg.2022-0578.
    Zhang Yaguo, Liang Wei, Guo Songfeng, et al. 2022. Analysis for effects of loess pore structure evolution on soil-water characteristics[J]. Journal of Engineering Geology, 30(6): 1998-2005. doi: 10.13544/j.cnki.jeg.2022-0578.
    Citation: Zhang Yaguo, Liang Wei, Guo Songfeng, et al. 2022. Analysis for effects of loess pore structure evolution on soil-water characteristics[J]. Journal of Engineering Geology, 30(6): 1998-2005. doi: 10.13544/j.cnki.jeg.2022-0578.

    黄土孔隙结构演化对其土-水特性影响分析

    ANALYSIS FOR EFFECTS OF LOESS PORE STRUCTURE EVOLUTION ON SOIL-WATER CHARACTERISTICS

    • 摘要: 作为黄土的关键水力参数之一,土-水特征曲线(SWCC)受到了土体孔隙结构特征的影响;然而目前还缺乏基于黄土沉积过程的孔隙演化对其土-水特性影响分析。本文在陕西泾阳县泾河南塬黄土剖面自上至下取L1、L2和L6黄土,通过扫描电镜定性分析黄土孔隙结构随沉积过程的演化特征,通过孔隙分布(PSD)曲线量化分析各层黄土的孔径分布特征;在此基础上,利用滤纸法测定黄土SWCC曲线,对比分析黄土SWCC随埋深的变化规律。通过Young-Laplace方程将孔径转化为对应的吸力值,将PSD与SWCC曲线采用同一吸力坐标放置一起,分析黄土孔隙结构分布与SWCC的对应关系。结果表明:随埋深的增大,黄土优势孔径及其分布密度减小;相应地,黄土SWCC的饱和段增长,进气值增大,过渡段变缓,持水能力增强。同时,在各层黄土取样位置取重塑土样,在确保制样含水率和干密度与对应原状土一致的情况下,对比分析重塑与原状黄土的孔隙结构与土-水特性,发现随着土层埋深的增大,两者之间孔隙结构差异增大,SWCC的差异也随之增大。

       

      Abstract: As one of the key hydraulic parameters of loess,soil-water characteristic curve(SWCC) is affected by soil pore structure characteristics. However,it lacks the studies about the effects of loess pore structure evolution on its soil-water characteristics. In this paper,L1,L2,and L6 specimens were taken from the loess platform at the southern bank of the Jinghe River in Jingyang County,Shaanxi Province. The evolution characteristics of loess pore structure during deposition were qualitatively analyzed through the scanning electron microscopy,and were quantitatively analyzed using the pore size distribution(PSD)curves. Meanwhile,the SWCCs of each layer of loess were measured by filter paper method,and the variation regularities along the loess profile were analyzed by comparisons of each other. The pore sizes were transformed into the potential suctions through Young-Laplace equation,and then the PSD and SWCC curves were plotted together with the same suction coordinate,finally the dependency of PSD and SWCC curves were analyzed. In details,the dominant pore sizes and their distribution densities decrease with soil depth increase. As a result,saturation sections and air entry values of SWCCs increased,and the transition sections turned to be gentler,which implied that the increasing of water retention capacities. In addition,comparing the PSD and SWCC of remolded soil specimen with that of intact ones,it could be found that the difference increased with soil depths,although both of them had the same water contents and dry densities.

       

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