DOI QR코드

DOI QR Code

Effect of particle size on direct shear deformation of soil

  • Gu, Renguo (State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences) ;
  • Fang, Yingguang (South China University of Technology) ;
  • Jiang, Quan (State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences) ;
  • Li, Bo (South China University of Technology) ;
  • Feng, Deluan (Guangdong University of Technology)
  • 투고 : 2021.05.10
  • 심사 : 2021.09.14
  • 발행 : 2022.01.25

초록

Soils are natural granular materials whose mechanical properties differ according to the size and composition of the particles, so soils exhibit an obvious scale effect. Traditional soil mechanics is based on continuum mechanics, which can not reflect the impact of particle size on soil mechanics. On that basis, a matrix-reinforcing-particle cell model is established in which the reinforcing particles are larger-diameter sand particles and the matrix comprises smaller-diameter bentonite particles. Since these two types of particles deform differently under shear stress, a new shear-strength theory under direct shear that considers the stress concentration and bypass phenomena of the matrix is established. In order to verify the rationality of this theory, a series of direct shear tests with different reinforcing particle diameter and volume fraction ratio are carried out. Theoretical analysis and experimental results showed that the interaction among particles of differing size and composition is the basic reason for the size effect of soils. Furthermore, the stress concentration and bypass phenomena of the matrix enhance the shear strength of a soil, and the volume ratio of reinforcing particles has an obvious impact on the shear strength. In addition, the newly proposed shear-strength theory agrees well with experimental values.

키워드

과제정보

This work was supported by the Open Research Fund of the State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences (Grant No. Z018019), the State Key Laboratory of Subtropical Building Science, South China University of Technology (Grant No. 2017KB16), and the National Key Scientific Instruments and Equipment Development Projects of China (Grant No. 41827807).

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