Journal of Guangdong University of Technology ›› 2018, Vol. 35 ›› Issue (04): 86-93.doi: 10.12052/gdutxb.170177

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Microstructure and Fractal Characteristics of Soft Clay during Triaxial Shear Process

Liu Yong-jian, Wu Jian-sheng, Peng Jian-wen, Xian Zhi-kun   

  1. Institute of Geotechnical Engineering, Guangdong University of Technology, Guangzhou 510060, China
  • Received:2017-12-26 Online:2018-07-09 Published:2018-06-06
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Abstract: The mineral composition and internal structure are the key factors in the determination of the physical and mechanical characteristics of the soft soil, and the variation of pore size and shape is obvious with the changes of soil properties. In order to investigate the microstructure and fractal characteristics of soft clay during the triaxial consolidated undrained shearing process, a lot of scanning electron microscopy (SEM) images of soft clay at different strain rates and strain stages were acquired. The equivalent pore size and fractal dimension of the soft soil were calculated. The results show that the particles and pores of soft clay have obvious fractal dimension characteristics while soft clay has the agglomerate-flocculation microstructure. The pores of soft clay before and after triaxial test are dominated by small pore size and medium pore size, and the large pore size distribution is less, which mainly exists in the undisturbed soil or the sheared soil. Soft clay has strain threshold affecting pore size distribution with strain rate in the shear process. With obvious fractal characteristics, the fractal dimension values (FDV) of pores varying from 1.891 to 1.750, the fractal dimension values of particles from 1.825 to 1.908, the FDV of particles increase and the FDV of pores decrease during the triaxial consolidated undrained shearing process, the size and shape of pores being relatively obvious.

Key words: soft clay, true triaxial consolidation undrained shear, microstructure, scanning electron microscopy

CLC Number: 

  • TU431
[1] 李彰明. 软土地基加固与质量控制[M]. 北京:中国建筑工业出版社,2011.
[2] 胡瑞林, 官国琳, 李向东, 等. 黏性土微观结构定量模型及其工程地质特征研究[M]. 北京:地质出版社, 1995.
[3] 刘勇健,李彰明. 软土物理力学性质指标与微结构参数的灰色关联-神经网络模型[J]. 岩土力学, 2011, 32(4):1018-1024.LIU Y J, LI Z M. Grey-relation analysis and neural networks model for relationship between physico- mechanical indices and microstructure parameters of soft soils[J]. Rock and Soil Mechanics, 2011, 32(4):1018-1024.
[4] 周翠英, 牟春梅. 珠江三角洲软土分布及其结构类型划分[J]. 中山大学学报(自然科学), 2004, 3(6):81-84.ZHOU C Y, MU C M. Distribution and microstructure classification of soft clay in the Pearl River Delta[J]. Acta Scientiarum Naturalium Universitatis Sunyatseni, 2004, 3(6):81-84.
[5] 张礼中, 胡瑞林, 李向全,等. 土体微观结构定量分析系统及应用[J]. 地质科技情报, 2008, 27(1):108-112.ZHANG L Z, HU R L, LI X Q, et al. Soil microstructure quantitative Analysis and its Application[J]. Geological science and technology information, 2008, 27(1):108-112.
[6] GYLLAND A S, RUESLÅTTEN H, JOSTAD H P, et al. Microstructure observations of shear zones in sensitive clay[J]. Engineering Geology, 2013, 163:75-88.
[7] TODORUK T R, LANGFORD C H, KANTZAS A. Pore-scale redistribution of water during wetting of air-dried soils as studied by low-field NMR relaxometry[J]. Environmental Science & technology, 2003, 37(12):2707-2713.
[8] BAYER J V, JAEGER F, SCHAUMANN G E. Proton nuclear resonance (NMR) relaxometry in soil science applications[J]. Open Magn Reson J, 2010, 3(1):15-26.
[9] 李彰明, 曾文秀, 高美连. 典型荷载条件下淤泥孔径分布特征核磁共振试验研究[J]. 物理学报, 2014, 63(5):057401LI Z M, ZENG W X, GAO M L. Nuclear magnetic resonance experimental study on the characteristics of pore-size distribution in muck under several typical loading cases[J]. Acta Phys Sin, 2014, 63(5):057401
[10] 许勇, 张季超, 李伍平. 饱和软土微结构分形特征的试验研究[J]. 岩土力学, 2007, 28(supp.):49-52.XU Y, ZHANG J C, LI W P. Research on microstructure fractal features of the saturation soft soil[J]. Rock and Soil Mechanics, 2007, 28(supp.):49-52.
[11] 张先伟, 孔令伟, 郭爱国, 等. 不同固结压力下强结构性黏土孔隙分布试验研究[J]. 岩土力学, 2014, 35(10):2794-2800.ZHANG X W, KONG L W, GUO A G, et al. Experiment study of pore distribution of strong structural clay under different consolidation pressures[J]. Rock and Soil Mechanics, 2014, 35(10):2794-2800.
[12] 吕海波, 赵艳林, 孔令伟, 等. 海相软土孔隙分布的分形特征及应用[J]. 桂林工学院学报, 2006, 26(1):50-53.LYU H B, ZHAO Y L, KONG L W, et al. Fractal feature of pore size distribution of a marine soft soil and its application[J]. Journal of Guilin University of Technology, 2006, 26(1):50-53.
[13] 谢和平.分形岩石力学导论[M].北京:科学出版社, 1996.
[14] 薛茹, 胡瑞林,毛灵涛. 软土加固过程中微结构变化的分形研究[J]. 土木工程学报, 2006, 39(10):87-91.XUE R, HU R L, MAO L T. Fractal study on the microstructure variation of soft soils in consolidation process[J]. China Civil Engineering Journal, 2006, 39(10):87-91.
[15] 周晖, 吴俊桦. 软土固结过程中基于分形理论的孔隙微观参数研究[J]. 广东工业大学学报, 2017, 34(4):41-46.ZHOU H, WU J H. A research on microscopic parameters of soft soil pore based on fractal theory in the process of consolidation[J]. Journal of Guangdong University of Technology, 2017, 34(4):41-46.
[16] 刘勇健, 刘湘秋, 刘雅恒, 等. 珠江三角洲软土物理力学性质对比分析[J]. 广东工业大学学报, 2013, 30(3):30-36.LIU Y J, LIU X Q, LIU Y H, et al. A contrastive analysis of the physico-mechanical properties of soft soils in the Pearl River Delta[J]. Journal of Guangdong University of Technology, 2013, 30(3):30-36.
[17] 刘勇健, 符纳, 陈创鑫, 等. 三轴冲击荷载作用前后软黏土的微观结构变化研究[J]. 广东工业大学学报, 2015, 32(2):23-27.LIU Y J, FU N, CHEN C X, et al. Study on microstructure changes of soft clay before and after triaxial impact load[J]. Journal of Guangdong University of Technology, 2015, 32(2):23-27.
[18] 康文武, 海相软土力学响应及加载速率效应研究[D]. 广州:广东工业大学土木与交通工程学院, 2017.
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