Effect of fractal particle size distribution on the mobility of dry granular flows
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In this article, the authors performed a numerical investigation on the kinetic behaviors of dry granular flows generated by the collapse of granular columns with different fractal particle size distributions (FPSDs) using the discrete element method.Abstract:
This paper performs a numerical investigation on the kinetic behaviors of dry granular flows generated by the collapse of granular columns with different fractal particle size distributions (FPSDs) using the discrete element method. The FPSD has a remarkable impact on the regime and mobility of a granular flow. As the fractal dimension of a granular assembly increases, the translational velocities of the particles increase in the horizontal direction, whereas the rotational velocities decrease. The number of particles involved in the horizontal spreading increases due to the decreasing intensity of the contact shearing particle behavior. These increased translational velocities in the horizontal direction effectively facilitate particle spreading. A boundary layer is formed at the front bottom of the granular body in which the clockwise rotational velocities of particles are significantly increased, thereby benefiting particle spreading. The whole front of the granular flow obtains an immense spreading velocity. Moreover, the translational and rotational characteristics are dependent on the particle size. Smaller particles tend to translate and rotate faster than larger particles because of the greater particle contact forces of the former. As the fractal dimension increases, medium- and large-size particles obtain less kinetic energy than do small-size particles. Therefore, small-size particles play a crucial role in the mobility of granular flows in a granular assembly with a high fractal dimension.read more
Citations
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Granular column collapse: Analysis of inter-particle friction effects
TL;DR: In this article , the authors investigated the effects of interparticle friction on the granular column collapses via the discrete element method (DEM) while eliminating the particle-size effects, and the motion patterns of the collapse were governed by the interparticles friction and initial aspect ratio through dimensional analysis.
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Analogical model tests on repeated surficial failure of dry granular slopes confined by retaining walls
TL;DR: In this article , the authors explored repeated surficial failure of granular slopes through indoor physical model tests and found that the failure presents low frequency and large scale for granular slope dominated by coarse particles.
References
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Journal ArticleDOI
Catastrophic Debris Streams (Sturzstroms) Generated by Rockfalls
TL;DR: In this paper, Bagnold et al. introduced the concept of "excessive travel distance" as a measure of the mobility of sturzstroms and showed that it is positively correlated with the size of the falling mass.
Journal ArticleDOI
Acoustic fluidization: A new geologic process?
TL;DR: In this paper, the authors proposed that the low strength apparent in these phenomena are due to a state of "acoustic fluidization" induced by a transient strong acoustic wave field and showed that acoustically fluidized debris behaves as a newtonian fluid with a viscosity in the range 100,000 to 10,000,000 P for plausible conditions.
Journal ArticleDOI
Entrainment of debris in rock avalanches: An analysis of a long run-out mechanism
Oldrich Hungr,Stephen G. Evans +1 more
TL;DR: In this paper, the authors describe two recent cases from British Columbia, Canada, where rockslides entrained substrate on a very large scale, influencing the character of the events.
Book ChapterDOI
The Mechanics of Rapid Granular Flows
TL;DR: In this article, the authors present a review of the classical papers of Bagnold and a discussion of the various modes and regimes of granular flow, such as vertical channels and inclined chutes.
Journal ArticleDOI
Axisymmetric collapses of granular columns
TL;DR: In this paper, experimental observations of the collapse of initially vertical columns of small grains are presented, mainly with dry grains of salt or sand, with some additional experiments using couscous, sugar or rice.