上海淤泥质黏土固结蠕变过程中结合水与微结构的变化

发布时间：2018-02-13 17:49

本文关键词： 软土固结蠕变结合水微结构蠕变机制　出处：《岩土力学》2017年10期 　论文类型：期刊论文

【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:pσ_k时主要是自由水的排出,宏观表现为衰减蠕变过程;pσ_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1μm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。
[Abstract]:In order to understand the creep mechanism of soft soil, one-dimensional consolidation creep test of Shanghai silt clay was carried out, which was combined with water test and scanning electron microscope (SEM) test. Quantitative analysis is made on the law of the variation of the bound water and the microstructure in the process of consolidation creep. The results show that the free water is mainly discharged at the ratio p 蟽 k, and the macroscopic manifestation is the attenuation creep process after the p 蟽 K, the osmotic bound water is gradually transformed into the free water discharge. The creep deformation and constant velocity creep rate increase obviously. The creep process is dominated by osmotic water, and the moisture content decreases exponentially with the increase of load as the structure unearthed by combined water is gradually solidified. There is a coupling effect between consolidation and creep. The loose skeleton flocculation structure evolves into a compact agglomeration flocculation structure. After creep adjustment the orientation of particles decreases and the number of small pores increases greatly. The small pore group with pore diameter of 1 渭 m is dominant. There exists load and the response mechanism of water and particle can explain the engineering phenomenon well.
【作者单位】：吉林大学建设工程学院;长安大学公路学院;核工业二七二地质大队;
【基金】：国家自然科学基金项目(No.41572257)~~
【分类号】：TU447

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