汤连生, 夏涵, 宋晶. 2015: 真空预压软土的排水通道演变特征. 工程地质学报, 23(s1): 179-183. DOI: 10.13544/j.cnki.jeg.2015.s1.028
    引用本文: 汤连生, 夏涵, 宋晶. 2015: 真空预压软土的排水通道演变特征. 工程地质学报, 23(s1): 179-183. DOI: 10.13544/j.cnki.jeg.2015.s1.028
    TANG Liansheng, XIA Han, SONG Jing. 2015: THE CHARACTERISTICS OF DRAINAGE CHANNELS EVOLUTION IN SOFT SOIL UNDER VACUUM PRELOADING. JOURNAL OF ENGINEERING GEOLOGY, 23(s1): 179-183. DOI: 10.13544/j.cnki.jeg.2015.s1.028
    Citation: TANG Liansheng, XIA Han, SONG Jing. 2015: THE CHARACTERISTICS OF DRAINAGE CHANNELS EVOLUTION IN SOFT SOIL UNDER VACUUM PRELOADING. JOURNAL OF ENGINEERING GEOLOGY, 23(s1): 179-183. DOI: 10.13544/j.cnki.jeg.2015.s1.028

    真空预压软土的排水通道演变特征

    THE CHARACTERISTICS OF DRAINAGE CHANNELS EVOLUTION IN SOFT SOIL UNDER VACUUM PRELOADING

    • 摘要: 真空预压加固软土时, 颗粒、孔隙及其结构的变化直接制约着软土的固结性质。本文以华南滨海海积淤泥为研究对象, 通过室内模拟实验, 扫描电镜实验从软土的排水机制出发, 通过分形的方法模拟了软土排水过程中的排水通道。真空预压初期, 排水通道发育, 水分受真空吸力牵引, 通畅流动, 排水通道视为直管, 随着排水持续进行, 排水通道收缩, 土颗粒吸附作用的影响增强, 水流携带部分细小黏粒移动, 甚至停滞, 造成结合水含量升高, 结合水的黏滞性和细颗粒的吸附性逐渐造成排水通道堵塞, 之后排水通道进一步缩小、闭合, 形成相互交错的网格状, 土体呈现明显的各向异性和非均质性。软土的排水过程也就是原排水通道被堵塞, 新排水通道形成的过程, 由此总结了软土真空预压下排水通道的演化规律。深入研究软土加固的微观结构变化对于该地区的工程建设的安全运营是非常有利的。

       

      Abstract: When vacuum preloading is performed on soft soil, changes in particle aggregates, void sizes and microstructure directly influence the consolidation process of the soft soil. In this paper, the marine soft soil sampling from south China coastal was adopted in the research.laboratory small-scale tests and scanning electron microscopy(SEM)tests were conducted to investigated the drainage mechanism of the soft soil. In addition, the fractal method was used to simulate evolution process of the drainage channels in the soft soil. In the initial stage of vacuum preloading, the drainage channels were developed and water was strongly attracted by vacuum suction. Therefore, the drainage channels could be deemed as straight pipes. In the subsequent stage, drainage channels shrank, enhancing the influence of soil particle adsorption. The water flow carrying tiny soil particles might be slowed down, leading to a higher adsorbed water content.the viscosity of adsorbed water and adsorb ability of fine particles gradually caused the blockage in drainage channels. At last, the drainage channels narrowed(even closed) and formed a mutually staggered grid. The soil showed obvious anisotropy and heterogeneity. Drainage process of the soft soil under vacuum preloading is essentially the process of the block up of the original drainage channels, followed by the formation of new drainage channels. A depth research in of microstructural change of soft soil in the reinforcement is advantageous for safe construction and operation of the engineering structure on the soft soil.

       

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