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Collapse of Granular Columns With Fractal Particle Size Distribution: Implications for Understanding the Role of Small Particles in Granular Flows
Author(s) -
Lai Zhiqiang,
Vallejo Luis E.,
Zhou Wei,
Ma Gang,
Espitia Jairo M.,
Caicedo Bernardo,
Chang Xiaolin
Publication year - 2017
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2017gl075689
Subject(s) - fractal , fractal dimension , mechanics , granular material , shearing (physics) , particle (ecology) , particle size distribution , particle size , flow (mathematics) , materials science , physics , geology , geotechnical engineering , mathematics , mathematical analysis , paleontology , oceanography
According to field measurements, the basic character of the particle size distributions obtained from the landslide accumulations is fractal. The collapse of the granular columns with fractal particle size distribution (FPSD) is performed numerically and experimentally to form dry granular flows and the mechanism of how FPSD affects the particle movements is then investigated. Numerical and experimental analyses show that particle flow mobility increases as the fractal dimension increases. Several linear relationships exist between the fractal dimension and flow mobility parameters. By analyzing the kinetics of granular flows, it is found that a large number of small‐sized particles will form a boundary layer where the particle shearing and velocities are remarkably increased and will thus have a lubricant effect on the flow mobility. Moreover, the number of particle collisions increases, and small‐sized particles are more likely to obtain higher spreading velocities via the greater contribution of particle interactions.