1. A micro–macro investigation of the capillary strengthening effect in wet granular materials
- Author
-
Ji-Peng Wang, Hai-Sui Yu, and Xia Li
- Subjects
Materials science ,Capillary action ,Effective stress ,Degree of saturation ,0211 other engineering and technologies ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Geotechnical Engineering and Engineering Geology ,Granular material ,Discrete element method ,Particle-size distribution ,Earth and Planetary Sciences (miscellaneous) ,Relative density ,Particle size ,Composite material ,0210 nano-technology ,021101 geological & geomatics engineering - Abstract
Wet granular materials are three-dimensionally simulated by the discrete element method with water bridges incorporated between particles. The water bridges are simplified as toroidal shapes, and the matric suction is constantly maintained in the material. A comparison with experimental tests in the literature indicates that the toroidal shape approximation may be one of the best choices with high practicability and decent accuracy. Mechanical behaviours of wet granular materials are studied by triaxial tests. Effects of particle size distributions and void ratios are investigated systematically in this study. The hydraulic limit of the pendular state is also discussed. It gives the capillary cohesion function which is not only determined by the degree of saturation but also positively correlated to relative density and particle size polydispersity and inversely proportional to mean particle size. Furthermore, the capillary strengthening effect is also analysed microscopically in aid of the Stress–Force–Fabric relationship, mainly in fabric anisotropy, coordination number and stress transmission pattern, which revealed the micro-mechanisms of the additional effective stress induced by capillary effect.
- Published
- 2017