土工基础 ›› 2021, Vol. 35 ›› Issue (3): 333-337.

• 专题论述 • 上一篇    下一篇

基于荷载效应下的软土孔隙特征研究

薛小杰,陈鸿宾,李文杰,宋 星   

  1. (桂林理工大学 广西岩土力学与工程重点实验室,广西桂林 541004)
  • 收稿日期:2020-04-09 修回日期:2020-04-17 出版日期:2021-06-25 发布日期:2021-06-26
  • 作者简介:薛小杰(1993-),男,硕士研究生,研究方向为岩土工程。
  • 基金资助:
    2019年广西研究生教育创新计划项目资助(项目编号:YCSW2019161)

Pore Size Distribution of Soft Soil under External Loading

XUE Xiaojie, CHEN Hongbin, LI Wenjie, SONG Xing   

  1. (Guangxi Key Laboratory of Geomechanics and Engineering, Guilin University of Technology, Guilin 541004)
  • Received:2020-04-09 Revised:2020-04-17 Online:2021-06-25 Published:2021-06-26

摘要: 为了探究荷载作用下软土孔隙结构的变化规律,对湛江软土进行100~800 kPa荷载下的一维固结试验,运用压汞技术测定了不同荷载下土样的孔隙组成,进一步分析了孔隙结构均匀性和分型特征。结果显示,r=0.25 μm可视为试验软土的临界孔隙半径,它将土壤孔隙分为可压缩孔(r≥0.25 μm)和不可压缩孔(r<0.25 μm)。随着荷载增加,可压缩孔线性减少,不可压缩孔则几乎保持不变。荷载越大,孔隙组成的均匀性越好,孔隙的均一系数C增大,即孔隙分布由复杂趋于集中。经历不同荷载的孔隙结构都具有良好的分形特性,分形维数介于2.98~2.94之间,且随着荷载增加而减小。

关键词: 固结, 压汞试验, 孔隙结构, 均匀性, 分形维数

Abstract: To investigate the variation of the pore size distribution of soft soil under the external loading, one-dimensional consolidation tests on Zhanjiang soft soil samples under vertical pressure of 100~800 kPa were performed. The pore size distribution of soil samples under different loads was characterized by the mercury intrusion method, and the pore structure was further analyzed by the uniformity and typing characteristics. The results show that the pore size r=0.25 μm can be regarded as the critical pore size of the tested soft soil, which divides the soil pore into compressible pore sizes (r≥0.25 μm) and incompressible pore sizes (r<0.25 μm). As the load increases, the compressible pore size decreases linearly, and the incompressible pore size remains almost unchanged. The larger the external load, the better the uniformity of the pore size distribution, and the uniformity coefficient C of the pores increases, that is, the pore size distribution tends to concentrate from complexity. The pore size structures experiencing different external loads have good fractal characteristics, and the fractal dimension is between 2.98 and 2.94, and decreases with increasing of external load.

Key words: Consolidation, Mercury Intrusion Test, Porous Structure, Uniformity, Fractal Dimension

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