基础理论与实验研究

上海淤泥质黏土固结蠕变过程中结合水与微结构的变化

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  • 1. 吉林大学 建设工程学院,吉林 长春 130026;2. 长安大学 公路学院,陕西 西安 710064;3. 核工业二七二地质大队,江苏 南京 210003
李硕,男,1992年生,博士研究生,主要从事软土蠕变和结合水方面的研究工作。

收稿日期: 2017-05-08

  网络出版日期: 2018-06-05

基金资助

国家自然科学基金项目(No. 41572257)。

Variations of bound water and microstructure in consolidation-creep process of Shanghai mucky clay

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  • 1. College of Construction Engineering, Jilin University, Changchun, Jilin 130026, China; 2. Highway College, Chang’an University, Xi’an, Shaanxi 710064, China; 3. No.272 Geological Party of Nuclear Industry, Nanjing, Jiangsu 210003, China

Received date: 2017-05-08

  Online published: 2018-06-05

Supported by

This work was supported by the National Natural Science Foundation of China (41572257).

摘要

为深入了解软土蠕变机制,开展了上海淤泥质黏土的一维固结蠕变试验、结合水测试试验和扫描电镜(SEM)试验,定量分析了固结蠕变过程中结合水和微结构的分阶段变化规律。结果表明:p?k后,渗透结合水逐渐转化为自由水排出,蠕变变形和等速蠕变率明显增大。蠕变过程由渗透结合水主导,随着结合水排出土的结构逐渐固化,含水率随荷载增加呈指数型衰减,存在固结-蠕变耦合效应。松散的骨架-絮凝结构演变为紧密的团聚-絮凝结构,颗粒在经历了蠕变调整之后定向性降低,小孔隙数量大量增加,孔径<1 μm的小孔隙组占优。存在荷载、结合水与颗粒的响应机制,其结果可以较好地解释工程现象。

本文引用格式

李 硕,王常明,吴 谦,张志敏,张兆楠, . 上海淤泥质黏土固结蠕变过程中结合水与微结构的变化[J]. 岩土力学, 2017 , 38(10) : 2809 -2816 . DOI: 10.16285/j.rsm.2017.10.005

Abstract

To understand creep mechanism of soft clay, one-dimensional consolidation creep tests, bound water measurement tests, and scanning electron microscope (SEM) tests on Shanghai mucky clay are conducted. The variations of bound water and microstructure in the process of consolidation-creep are quantitatively analyzed. The results show that, free water discharged under condition of p?k. Meanwhile, the creep strain and steady-state creep strain rate increase significantly. The creep process is dominated by osmotic bound water. The microstructure is solidified gradually with bound water discharging and the water content decreases exponentially with increasing loads. Deformation of soft clay is caused by consolidation-creep coupling effects. The original loose skeleton-flocculated structure translates into dense reunion-flocculated structure. The directionality of particles decreases under the long-term creep adjustment. The quantity of fine pores increases massively after creep tests and the pores with diameters less than 1 μm in dominancy. The response mechanism among loads, bound water and particles can explain engineering phenomenon well.
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