长江科学院院报 ›› 2018, Vol. 35 ›› Issue (1): 117-122.DOI: 10.11988/ckyyb.20160916

• 岩土工程 • 上一篇    下一篇

固化疏浚土宏-微观力学特性室内试验研究

史旦达, 齐梦菊, 许冰沁, 刘文白   

  1. 上海海事大学 海洋科学与工程学院,上海 201306
  • 收稿日期:2016-09-06 出版日期:2018-01-01 发布日期:2018-01-11
  • 作者简介:史旦达(1979-),男,浙江舟山人,副教授,博士,主要从事海洋岩土工程、海洋资源开发利用等方面的研究工作。E-mail:shidanda@163.com
  • 基金资助:
    国家自然科学基金项目(50909057, 41772273);上海市软科学研究重点项目(16692105400);上海市教育委员会科研创新项目(15ZZ081)

Indoor Test on the Macro-and-microscopic MechanicalProperties of Solidified Dredged Soils

SHI Dan-da, QI Meng-ju, XU Bing-qin, LIU Wen-bai   

  1. College of Ocean Science and Engineering, Shanghai Maritime University, Shanghai 201306, China
  • Received:2016-09-06 Online:2018-01-01 Published:2018-01-11

摘要: 以上海某沿海港域吹填场地的砂土和黏土为试验土料,通过掺入自制固化剂和WK-G1型固化剂在室内制备固化疏浚土试样,采用土力学直剪和压缩试验方法,着重分析了固化剂掺量和养护龄期对固化疏浚土试样抗剪强度与压缩变形特性的影响。此外,利用扫描电镜(Scanning Electron Microscope, SEM)从微观层面分析了固化疏浚土试样的结构特征,采用Image-Pro Plus(IPP)图像处理软件和自编MatLab程序,提取和分析与颗粒、孔隙及颗粒表面起伏相关的微观结构分维数,基于分形理论,探讨了固化过程中试样微观结构变化与宏观强度及变形特性的宏微观关联。试验结果表明:无论砂土还是黏土,试样压缩模量和抗剪强度均随固化剂掺量和养护龄期的增加呈现出非线性增长规律,在微观机制上,试样压缩模量和抗剪强度的提升与颗粒平均面积与平均半径的增加密切相关。

关键词: 固化疏浚土, 抗剪强度, 压缩变形, 微观结构, 分维数

Abstract: In this paper, both the macroscopic and microscopic mechanical properties of solidified dredged soil were experimentally studied. First, the influence of curing agent dosage and curing age on shear strength and compressive deformation behaviors were analyzed through direct shear test and 1-D compression test. The solidified dredged soil samples were prepared by adding self-made curing agent and commercial curing agent WK-G1 into the sandy soil and clay collected from a large hydraulic fill field in Shanghai coastal area. In addition, the variation of the microstructure of soil samples during solidification was analyzed via scanning electron microscopy. Based on the fractal theory, the fractal dimensions related to particle and void sizes, particle and void distributions, and particle surface fluctuation were extracted using image processing software Image-Pro Plus and self-coded MatLab program. The relationship between microstructure parameters and macro-mechanical property indices was quantitatively explored. Results suggest that for both sandy soil and clay, the compressive modulus and shear strength increased linearly as curing agent dosage and curing age increased; while in microscopic sense, the growth in compressive modulus and shear strength is closely related with the mean area and mean diameter of particle.

Key words: solidified dredged soils, shear strength, compression deformation, microstructure, fractal dimension

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