吹填土固结过程中结构与物理性质变化

吹填土的固结过程是土颗粒从无序不规则排列到有序较规则排列,直到絮凝并形成较稳定土结构的过程.在吹填土室内模拟加固试验的过程中,在指定位置和深度采取土样,进行土样的基本物理性质和微结构的测试.对土样微观结构、颗粒粒度、颗粒丰度、颗粒定向性以及宏观基本物理性质变化进行分析.结果表明:深部颗粒团聚程度大于浅部.浅部颗粒水平向的变化大于竖向,深部竖向和水平向的变化程度相似.结构单元体粒径2,μm的颗粒数量不断减小,20,μm颗粒数量不断增加.颗粒丰度有减小趋势.土颗粒定向于某个或某几个方向.定向性和丰度的增加促使颗粒的团聚.该过程是土颗粒由不稳定向稳定状态不断过度的过程.集粒的形成大幅度改善宏观物理性质,表现为含水率的减少和密度的增加.

Changes of Structure and Physical Properties in the Process of Dredger Fill Consolidation

The consolidation process of dredger fill is one in which soil particles change from disorder and irregularityto order and regularity, flocculate and form a more stable soil structure. In the process of indoor simulation consolida-tion test for dredger fill, soil samples were taken at the specified position and depth, and the basic physical proper-ties and micro-structure of the samples were tested. The microscopic structure, particle size, particle abundance,particle orientation and the change in macroscopic physical properties of dredger fill were analyzed. The resultsshowed that the agglomeration degree in the deep part is greater than that in the shallow part. In the shallow part, thechange of particles in the horizontal direction is greater than that in the vertical direction, while in the deep part, thechange degrees in both vertical and horizontal directions are similar. The number of particles 〈 2 μm decreases con-tinuously, while the number of particles 〉 20 μm keeps increasing. The abundance of particles decreases. Soil parti-cles are directed at one or several directions. The increase of orientation and abundance prompted the agglomeration ofparticles. This process is a transformation process of soil particles from unstable to stable state. The formation of setparticles would significantly improve the macroscopic physical properties, with a reduction of moisture content andan increase of density.