影响黄土湿陷性因素的微观试验研究

发布时间：2019-05-27 12:30

【摘要】：借助扫描电子显微镜和光学数码显微镜,分析了不同含水率黄土试样表面微区结构变化与黄土湿陷性的关系和不同埋深土样在水与外力共同作用下湿陷前后微观结构的变化特征。利用图像处理软件对所获取的微结构图像进行研究,分析了黄土湿陷前后土样中大、中、小孔隙和微孔隙数量的变化。结果表明:湿陷后比湿陷前土样微孔隙增多31.18%,小孔隙增多54.07%,中孔隙减少30.49%,大孔隙减少90.14%。这说明随着压力的不断增大,黄土中的孔隙被逐渐压缩,大孔隙和中孔隙的数量逐渐减少,小孔隙和微孔隙的数量逐渐增加,为黄土的湿陷变形提供了充分的空间。讨论了土样中4类孔隙对黄土湿陷的贡献量,从微观角度综合分析了黄土湿陷的成因机理。
[Abstract]:With the help of scanning electron microscopes and optical digital microscopes, The relationship between the surface microzone structure change of loess samples with different moisture content and the collapsibility of loess was analyzed, and the microstructure of soil samples with different buried depths under the action of water and external force before and after collapsibility was analyzed. The microstructure images obtained were studied by image processing software, and the changes of the number of large, medium, small pores and micropores in soil samples before and after loess collapsibility were analyzed. The results show that the micropores, small pores, medium pores and macropores of soil samples after collapsibility are 31.18%, 54.07%, 30.49% and 90.14%, respectively. This shows that with the increase of pressure, the pores in loess are gradually compressed, the number of macropores and middle pores is gradually reduced, and the number of small pores and micropores increases gradually, which provides sufficient space for the collapsible deformation of loess. The contribution of four kinds of pores in soil samples to loess collapsibility is discussed, and the genetic mechanism of loess collapsibility is comprehensively analyzed from the microscopic point of view.
【作者单位】：长安大学地质工程与测绘学院;地质灾害防治与地质环境保护国家重点实验室(成都理工大学);内蒙古农业大学水利与土木建筑工程学院;四川省煤田地质工程勘察设计研究院;
【基金】：国家自然科学基金面上项目(41172255);国家自然科学基金应急管理项目(41440044) 地质灾害防治与地质环境保护国家重点实验室开放资金资助项目(SKLGP2012K028) 西安长庆科技工程有限责任公司资助项目(CTEC(2014)Z-KY-013) 中央高校基本科研业务费资助项目(2014G2260008)资助
【分类号】：TU475.3

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