中文摘要：

利用河海大学自行研制的岩土材料微细结构光学测试系统，进行三轴应力下黏性土微结构特征参数的定量分析，研究三轴应力作用下黏性土微结构的演化规律及其力学特性。研究结果表明；重塑黏性土样在围压较低时，以均匀性破坏为主，局部化变形破坏为辅；荷载作用下，颗粒或孔隙的聚合和崩解同时发生，没有那种过程占据明显的优势；压缩过程中，颗粒所占面积增加，孔隙所占面积减小；颗粒的初始扁圆度越高，压缩过程中颗粒圆度值降低幅度越大，颗粒形状变化也越明显；随着制样含水量的提高，颗粒圆度不断增大，其空间排列变得紧密；随着具有微膨胀特性的黏性土含水量的增加，土体的强度显著下降，加载后的应变率增大。

英文摘要：

By means of the optics test system completely developed by Hohai University for geomatenal＇s microstructure, the microstructure changes of cohesive soils under triaxial stress were quantitatively studied and the correlative characteristic parameters were extracted and analyzed. Then the microstructure evolution regularity of cohesive soils under triaxial stress and its effect on mechanical behavior were studied. Results indicate that the remolded samples＇ collapse mode of cohesive soils under lower confining pressure is based solely on symmetrical deformation and based accessorially on localized deformation. Under load action, particle conglomerate or pore aggregation and disintegration occurs at the same time and no action achieves distinct advantage over another action. As a whole the particles surface ratio increases and the pores surface ratio decreases during compression process. The initial flat roundness of particle is higher, the decrease range of particle roundness will be larger during compression process and the change of particle shape will be more evident. The roundness of particles continuously largens and the spatial arrangement of particles becomes compacted as water content advances. The soil strength descends evidently and its strain rate increases as water content of cohesive soil with low swelling property increases.