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
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