粘土矿物成分与剪切强度的相关关系分析

为探究矿物成分对土体强度的影响规律，对纯的粘土矿物进行扫描电镜和X射线衍射试验，确定其成分及微观组构. 对人工配制单一成分粘土，开展不同初始含水率状态下的直剪试验，分析了含水率对各单一矿物粘性土的粘聚力、内摩擦角的影响；对比不同粘土矿物人工配土抗剪强度随含水率变化规律，结合各单一矿物的微观组构特征，探讨了粘土矿物成分对剪切强度的影响. 研究结果表明:高岭石的粘聚力、内摩擦角均随含水率增大单调减小；伊利石和蒙脱石在含水率分别为18%和25%时出现粘聚力峰值；含水率小于20%时，蒙脱石内摩擦角随含水率增加呈线性增大；大于20%时，内摩擦角线性减小. 

Correlation Analysis between Clay Mineral Composition and Shear Strength

The influence of mineral composition on soil shear strength was investigated in this study. Using scanning electron microscopy and X-ray diffraction measurements, the composition and microstructure of pure clay minerals was obtained. Single-component clay samples were manually prepared with different initial water contents, and direct shear tests were performed to analyse the influence of moisture content on the cohesive force and internal friction angle of single mineral viscous soil. The results show that the cohesion and friction angle of kaolinite decrease monotonically with an increase in water content. Illite and montmorillonite exhibit peak cohesion when the water content is 18% and 25%, respectively. When the moisture content is approximately 20%, the maximum internal friction angle for montmorillonite appears.