中文摘要：

利用三轴固结不排水试验测出了不同含水率下黄土的抗剪强度参数。原状试样取自陕西省黄陵县一高边坡的第五层黄土,将含水量配制为3%、6%、11%、16%、21%、26%、30%和32%,围压设置为0、100、200、300、400和500 kPa进行试验。结果表明,含水量对黄土有效残余抗剪强度的影响主要体现在粘聚力上,当含水率低于塑限时,有效残余粘聚力随着含水率的增加明显降低,但是当含水率大于塑限时,有效残余粘聚力基本保持不变;有效残余内摩擦角和含水率没有明显的相关性。黄土强度参数随含水量的这种变化规律体现了黄土的非饱和特性,由于有效内摩擦角体现的是有效应力和抗剪强度之间的线性关系,排除了孔隙水压力的影响,与含水率无关;粘聚力随含水量减小而增加是由于基质吸力增大而引起,黄土的粘聚力中包含了基质吸力的作用。

英文摘要：

Based on CU triaxial test,shear strength under different moisture content were investigated. Intact samples on the fifth loess（ L5） were taken from a high cut slope of Huangling County,Shaanxi Province, China. The specimens for CU triaxial test were prepared as 8 groups with the expected moisture content of 3%,6%,11%,16%,21%,26%,30% and 32% respectively. Then each group has 6 specimens which were consolidated under the confining stress（ σ3） of 0,100,200,300,400 and 500kPa in the triaxial tests. The results suggest that the moisture content mainly affects the cohesion rather than the friction angle. when the moisture content is below plastic limit,with the increase of moisture content the effective cohesion goes down rapidly,as the moisture content is higher than plastic limit,effective cohesion keeps invariable; while the effective friction angle φ＇is independent of moisture content. The law of strength parameters of loess change with moisture content reflects the characteristics of unsaturated loess. The effective internal friction angle, reflecting the linear relationship between effective stress and the shear strength and eliminating the influence of pore water pressure,has nothing to do with the moisture content; the decrease of the cohesive force with the increase of water content is caused by the increase of matric suction,So the matric suction is included in the cohesive force of loess.