Discrete element analysis of dry granular flow impact on slit dams

Abstract

Slit dam is an open-check barrier structure widely used in mountainous regions to resist the destructive impacts of granular flows. To examine the dynamics of granular flow impact on slit dams, a numerical study by discrete element method (DEM) is presented in this article. The study considers dry granular materials flowing down a flume channel and interacts with slit dams installed at the lower section of the flume. The particle shape is explicitly considered by particle clumps of various aspect ratios. The slit dams are modeled as rigid and smooth rectangular prisms uniformly spaced at in the flume. Four key stages of granular flow impact on the slit dams have been identified, namely, the frontal impact, run up, pile up, and static deposition stages. In the impact process, the kinetic energy of the granular flow is dissipated primarily by interparticle friction and damping. The trapping efficiency of the slit dams decreases exponentially with the relative post spacing, while it increases with the particle clump aspect ratio. The numerical results can provide new insights into the optimization of relative post spacing for slit dam design.

Multi-phase flow simulation of landslide dam formation process based on extended coupled DEM-CFD method

“…r / F v gh = , where v is the granular flow velocity and h is the flow depth, which is closely related to the impact behavior of granular flow. In the field observation, the Froude number normally ranges from 0.5 to 7.6 (Gong et al, 2021). The Froude number of granular flow ranged from 2.9 to 5.3 in this study.…”

A Study on the Unstable Evolution Characteristics of Loose Particle Slopes under Dynamic Supply of Material Sources

“…Texier et al [8][9][10][11][12][13] investigated the effects of natural angle of repose, particle gradation distribution, particle size, water content, particle roundness, particle gradation and other factors on bulk slope stability. Fan Limin et al 14 obtained through theoretical analysis that the main factors affecting the runoff flow rate at the surface of the slope and the seepage flow rate inside the slope body are slope gradient, runoff water depth, porosity and permeability of the bulk granular body of the slope, and the flow rate increases with its increase Marchelli, M. et al 9,10,[15][16][17][18][19][20][21] conducted a study on the preventive and curative measures against disasters of the bulk granular slopesretaining walls, slit dams, and detention barriers. Li, X. Y.et al 22 investigated the effect of earthquakes on the stacking morphology of bulk slopes and found that the direction of vibration had a significant effect on the shape of the stacks, and the values of the stroke were larger when the direction of vibration was horizontal than when the direction of vibration was vertical, whereas the values of the stacking width and thickness were smaller than when the direction of vibration was vertical.…”

Three-Dimensional Discrete Element Modelling of Granular Avalanche Under Multiple Flow Conditions

“…Some studies compared velocities at the tip of flowing granular materials [5,6]; however, their validity was often confirmed by only the final deposition shape [7,8]. In these studies, the granular avalanche experiments, which were performed for comparing the results with those of numerical simulations, considered constant slope angles and slope heights.…”