摘要
非饱和土中吸力的测量比较困难,选择饱和度作为参数在非饱和土研究中具有重要的实用价值.在改进的常规三仪上对不同干密度、不同饱和度的云南红黏土试样进行不排气不排水三轴试验,试验过程中试样出现了明显的剪胀现象.当试样干密度较大时,即使饱和度较大也出现了剪胀;而当试验干密度较小时,在饱和度较大时剪胀消失.通过微观机理可以很好地解释这种剪胀现象,剪胀主要由于试验过程中孔隙气压力所造成颗粒间力矩不平衡引起的,而当干密度较小、饱和度较大时,孔隙气在围压作用下会溶于水,这种颗粒间的不平衡力矩消失,剪胀现象也随之消失了.
It is difficult to measure matric suction in unsaturated soil. Using saturation as a parameter is valua- ble for unsaturated soil research. A series of improved triaxial compression tests were performed on Yunnan red cohesive soil with different initial saturation degrees and different dry bulk densities. The dilatation occurred frequently during the tests. When the soil dry bulk density was high, the dilatation of samples with high satu- ration degrees also occurred. The dilatation disappeared when soil dry bulk density was small and saturation degree was high. The dilatation can be well explained through microscopic mechanism. The dilatation was caused by lopsided moment and the lopsided moment was caused by pore air pressure. When the soil samples with high saturation degrees had small dry bulk densities, the pore air dissolved in the water and the dilatation disappeared.
出处
《郑州大学学报（工学版）》
CAS
北大核心
2012年第5期53-56,共4页
Journal of Zhengzhou University（Engineering Science）
关键词
红黏土
三轴试验
体变
剪胀
red cohesive soil
triaxial test
volumetric deformation
dilatation
