非饱和红黏土的强度特性研究

红黏土是一种富含胶结作用物质的塑性黏土，与普通黏性土相比，红黏土的强度特性更为复杂。通过直剪仪对不同含水率和不同含丙三醇溶液的重塑红黏土进行了抗剪强度试验，发现红黏土的强度、黏聚力随着溶液含量的增加出现了“双峰”值现象，且内摩擦角基本保持不变，用丙三醇溶液替代水溶液配制的土样其强度有了明显的降低。结合核磁共振仪对红黏土试样的孔径分布研究情况，基于Bishop提出非饱和土的有效应力原理，探讨了非饱和红黏土的强度随含水率变化出现“双峰”现象的影响机制，认为红黏土本身孔径大小分布特征起了非常重要的作用。

Research on strength characteristics of unsaturated red clay

Red clay is one of the special soils which contains cementing material. Compared with common cohesive soils, the strength characteristics of red clay are more complicated. Some direct shear tests are performed on the unsaturated red clay samples with water and propanetriol solution; and the experimental results show that the strength and cohesion of samples exhibit double peaks of strength increasing with the increase of solution content; while the internal friction angle does not change. Besides, the strength of samples diminishes obviously with the propanetriol solution instead of water. Based on Bishop's effective stress for unsaturated soil and the characteristic of pore distribution acquired by NMR tests, the impact mechanism of pore distribution characteristic on strength is discucsed, and a conclusion is drawn that pore distribution characteristic has much effect on strength of red clay samples.