Microstructual Changes and Compressive Strength by means of Consolidation Methd,

本文研究的对象是粘性土固结过程中的微观结构变化，以及一维固结法、Ko固结法和各向同性固结法的固结和抗压强度特征。进一步研究了土的抗剪强度各向异性与取向的关系。本研究使用了5种再固结粘性土和近20种原状粘性土。这些样品进行了一维、Ko和各向同性固结试验。对这些固结样进行了无侧限压缩试验和固结不排水三轴压缩拉伸试验。用扫描电镜观察了颗粒取向的变化。主要研究结果如下：1。Ko固结试验的一维固结特征与趋势相似。但各向同性固结的体应变以平均主应力计算小于一维固结，轴向应变与偏应力成正比。一方面，随着固结压力的增大，各黏土颗粒和/或坡体在一维固结和高强固结中的取向普遍趋于平行于水平面，另一方面，在各向同性固结中趋于随机结构。相同孔隙比下，一维固结试件的无侧限抗压强度高于各向同性固结试件。强度差与各向同性固结压力成正比减小。分析了孔隙率、土体取向与无侧限抗压强度或渗透性之间的关系。

The objects in this study are microstructual changes in consolidation process, the characteristics of consolidation and compressive strength by means of one-dimentional, Ko, and isotropic consolidation methods, in cohesive soils. Furthermore the correlations of shear strength anisotropy and orientation of peds are investigated.Five kinds of reconsolidated clayey soiles and approximately twenty kinds of undisturbed cohesive soils were used in this study. Theses samples were carried out one-dimentional, Ko, and isotropic consolidation tests. Unconfined compression test and consolidated undrained triaxial compression and extension tests were performed on these consolidated samples. A scanning electron microscope were used to observe the changes in particle orientation.The main results obtained are as follows:1. The characteristics in one-dimentional consolidation of Ko consolidation test are similar to tendancy. But the volumetric strain of isotropic consolidation in terms of the mean principal stress is smallev than one-dimentional consolidation, and the axial strain is proportional to the deviator stres.2. On the one hand the orientation of each clay particle and / or ped in one-dimentional and Ko consolidation generally becomes parallel to horizontal plane with the increase in consolidation pressure, the other hand in isotropic consolidation becoms to ramdom structure.3. In same void ratio, unconfined compressive strength in one-dimentional consolidation specimen is higher than isotropic consolidation specimen. The differen of strength decreases in proportinal to isotropic consolidation pressure.4. It is illustrated that the relationship between the void ration, orientafion of peds, and unconfined compressive strength or permeability.