三轴应力下黏性土微细结构试验

Experimental study on microstructure of cohesive soil under triaxial stress

利用自行研制的微细结构光学测试系统,对三轴应力下黏性土的微细结构图像进行了连续采集,提取了相应的微细结构量化参数,对微细结构的演化特性进行了分析。结果表明:随着荷载的增加,颗粒集聚体排列向着杂乱无序的方向发展,导致土体抵抗外界荷载的能力不断降低;在荷载作用下,土体通过颗粒集聚体形态和排列形式的调整变化,逐步向稳定的承载形式过渡,使变形向逐渐减小的趋势发展;颗粒集聚体和孔隙的变化是相互关联的。

The self-designed optical testing system for mierostructure was employed for eontinuous image acquisition of microstructure of cohesive soil. Then, the quantitative parameters of the microstructure were extracted, and the variation characteristics of the microstructure were analyzed. Some conclusions are drawn： with the increase of loads, the particle conglomerates tend to be in a disordered form, which decrease the capacity of soil mass against the external loads; with the adjustment of arrangement form of particle conglomerates, the soft mass under the action of loads develops towards a stable loadbearing state, and the deformation of soil mass gradually decreases; the variations of particle conglomerates and pores are related to each other.