应力状态对土-水特征曲线的影响规律

摘要

In order to systematically investigate the influences of various kinds of stress states on the soil-water characteristic curve ( SWCC ) , an unsaturated soil oedometer and a double-cell triaxial apparatus were used to study the influences of K0 and the isotropic stress state on the SWCC of the compacted clay soil taken from Xinxiang, in Henan Province. The test results show that the effects of isotropic and K0 compression on the SWCC were similar in the low stress regime (<100 kPa) , and the void ratio after consolidation controlled the shape of the SWCC. The air-entry value increased with the decrease of the void ratio, and the gradients of the drying and wetting curves increased with the increase of the void ratio. In addition, the hydraulic hysteresis between the drying and wetting curves was more significant with a higher void ratio.%为系统地探讨不同应力状态对土-水特征曲线的影响,以河南新乡地区的黏土为对象,采用非饱和固结仪与双室三轴仪分别研究K0和等向应力状态对压实黏土的土-水特征曲线的影响规律.试验结果表明:低应力(小于100kPa)下等向应力状态对土-水特征曲线的影响与K0状态相似,固结后孔隙比不同决定着土-水特征曲线的形状有所差异.土体的空气进入值随着孔隙比的减小而增加,土体进气后,干燥与增湿曲线的斜率随着孔隙比的增加而增大,且孔隙比较大时土体的滞回特性更明显.