桂林红粘土的物质组成及其工程地质性质特征

经差热、X衍射、扫描电镜鉴定和化学成分测试及近千组常规土工试验资料统计分析表明,物质成分上桂林红粘土主要由高岭石、伊利石、绿泥石等次生粘土矿物组成,并含有少量的蒙脱石、蛭石及混层矿物,铁铝氧化物高度富集,粘粒含量一般都在50%以上;工程地质性质上桂林红粘土具有天然含水量、孔隙比、液限及抗剪强度较高,容重、饱和度、比表面较大,压缩性、交换容量较低,透水性、崩解性较小及中-弱胀缩性等特点.

Material Compositions and Engineering Geological Properites of Guilin Red Soil

On the basis of the analysis of differential thermal, X-ray diffraction,electron microscope scanning and about thousand groups of geotechnical test data,the material compositions and engineering geological properties of Guilin red soil are as follows:(1) The second clay minerals is made mainly of kaolinite,illite and chlorite and so on in the red soil.In addition,there are little minerals of montmorillonite and vermiculite.(2) The iron and aluminum oxides are rich and the content of clay grain is usually large than 50% in the red soil.(3) The water content,the void ratio,the liquid limit and the shearing strength are high;the natural unit weight,the saturability and the specific surface area are large;the cation exchange capacity,the compressibility,the permeability coefficient and the slaking are small.(4) The red soil possesses weak-moderate expansion and shrinkage properties.