杭州饱和软土固结过程微观结构试验研究

发布时间：2018-06-02 03:34

本文选题：饱和软土 + 微观结构　；参考：《中南大学学报(自然科学版)》2014年06期

【摘要】：软土的工程特性很大程度上取决于土体内部的孔隙特征及其变化规律,为探讨软土固结过程中压缩性及其微观结构变化机理,对杭州结构性黏土进行室内固结试验,通过液氮真空冷冻干燥技术制备微观土样,借助扫描电镜试验获取微观结构图像,用计算机图像处理软件定量分析土体孔隙特征随着固结压力的变化规律,并讨论微观结构参数与土体压缩性的相关机制。结果表明:固结压力将显著改变软土的孔隙尺度、分布、排列、形态等特征,随着固结压力的增加,孔隙数先增加后减少、微小孔隙的比例增加、均一化程度提高、定向性增强、复杂程度降低;土体微观结构参数与压缩系数随着固结压力的变化规律有很好的相关性,均在固结前期显著变化,在固结后期变化趋于平缓;用土的微观结构变化解释和验证宏观试验土体的物理力学特性是可行的。
[Abstract]:To a great extent, the engineering characteristics of soft soil depend on the internal pore characteristics and its variation law. In order to study the compressibility and the mechanism of microstructure change in the consolidation process of soft soil, the consolidation tests of Hangzhou structural clay are carried out in laboratory. The microcosmic soil samples were prepared by liquid nitrogen vacuum freeze-drying technique. The microstructure images were obtained by scanning electron microscopy (SEM). The pore characteristics of soil with consolidation pressure were quantitatively analyzed by computer image processing software. The correlation mechanism between microstructure parameters and soil compressibility is discussed. The results show that consolidation pressure will significantly change the pore size, distribution, arrangement and morphology of soft soil. With the increase of consolidation pressure, the number of pores increases first and then decreases, the proportion of tiny pores increases and the degree of homogenization increases. The change of soil microstructure parameter and compression coefficient with consolidation pressure has a good correlation, both of them change significantly in the early stage of consolidation, and tend to change slowly in the later period of consolidation. It is feasible to explain and verify the physical and mechanical properties of the soil mass by using the microstructure of the soil.
【作者单位】：浙江大学滨海和城市岩土工程研究中心;浙江大学软弱土与环境土工教育部重点实验室;
【基金】：国家自然科学基金资助项目(50778162,51178422)
【分类号】：TU447;TU411

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