合徐高速北段膨胀土的物质组分及微结构研究

Research on the composition and microstructure of expansive soils in the north section of Hefei-Xuzhou Expressway

文章以X射线衍射为主,并结合化学全分析、偏光显微镜、扫描电镜对合徐高速北段沿线经过的蚌埠、怀远和宿州地区的膨胀土进行矿物化学成分以及微结构特征研究,探明膨胀土的液限、塑性指数以及胀缩性与其矿物组分、阳离子交换容量、氧化度及微观结构之间的关系,并对其微结构进行分类。研究表明:膨胀土在其蒙脱石含量基本相等的情况下,伊利石含量的多寡对膨胀土工程性质的控制影响十分明显,而膨胀土的氧化程度则是控制膨胀土工程特性的另一个重要因素。

Abstract：The mineral composition of expansive soils in the north section of Hefei-Xuzhou Expressway is investigated mainly by means of X-ray diffraction analysis（XDA） together with chemical analysis, the polarizing microscope and the scanning electron microscope（SEM）. The relationship between the engineering properties of expansive soils and their mineral composition, capability of exchangeable cat ions（CEC）, oxidation degree and mierostructure is studied. The microstructure of the soils is also classified. Study shows that the engineering properties of expansive soils are mainly controlled by their mineral composition, CEC, oxidation degree and microstructure. The influences of the content of illite and the oxidation degree are also significant.