Data from: The retard-boost effect of fragmentation in rock avalanches
Data files
Feb 24, 2025 version files 246.49 KB
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Dataset.xlsx
241.09 KB
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README.md
5.40 KB
Abstract
This study presents a micro-mechanical numerical investigation into the fundamental aspects of progressive fragmentation and its effects on rock avalanche dynamics. The simulations involve breakable rock assemblies that are released along an inclined plane and subsequently collide onto a horizontal surface. A discrete-continuous numerical model is adopted to effectively capture progressive particle breakage and complex interparticle interactions. By incorporating variations in fracture mechanics parameters, the model systematically evaluates the influence of progressive grain fragmentation on rock avalanche dynamics. A multi-layer analysis method and the interlayer transmitting coefficient is proposed to analyze the temporal and spatial kinematics, stress distribution and the ongoing particle size reduction process. The results indicate that grain fragmentation significantly influences rock avalanche motion, identified as the "retard-boost" effect in this study. At low fragmentation degree, densely packed rock particles exhibit an interlayer transmitting effect, with kinematic energy dissipation primarily resulting from grain breakage. Conversely, full mobilization of rock fragmentation from the base upwards enhances flow mobility by reducing basal friction through the agitation of fragments. The findings indicate a competition between positive feedback, which enhances rock avalanche mobility at high fragmentation levels, and negative feedback, which results in energy dissipation at low fragmentation levels, with the predominance of these effects varying according to the degree of fragmentation.
https://doi.org/10.5061/dryad.m905qfv9x
Description of the data and file structure
This dataset includes the results of a numerical investigation into the fundamental aspects of progressive fragmentation within rock avalanches. This model is developed based on the platform of the commercial software ABAQUS. The data supports the figures in the associated manuscript, providing detailed information on velocity distributions, stress evolution, energy dissipation, and particle dynamics. This link includes dataset of figures in this manuscript.
Files and variables
File: Dataset.xlsx
Overview
The dataset is organized into an Excel file, where each sheet corresponds to a specific figure in the manuscript. Each sheet contains the raw or processed data used to generate the respective figure. Below is a detailed description of the data in each sheet.
Sheet of Figure 1
This sheet contains data on the equivalent coefficient and apparent coefficient of rock avalanches, derived from three sources:
(1) Manzella's Study (Columns A-C):
- Column B: Equivalent coefficient from Manzella's study.
- Column C: Apparent coefficient from Manzella's study.
(2) The Former Study (Columns D-F):
- Column E: Equivalent coefficient from the former study.
- Column F: Apparent coefficient from the former study.
(3) This Study (Columns H-Q):
- Columns P: Equivalent coefficient from this study.
- Columns Q: Apparent coefficient from this study.
Sheet of Figure 2
- Rows 1-10: Time evolution of the breakage degree t10 for Cases S1-S4, from 0.5s to 5s.
- Rows 13-19: Average particle size along depth for Cases S1-S4, including refined results.
Sheet of Figure 3
- Rows 1-13: Evolution of the overall velocity of the granular mass in the horizontal direction.
- Rows 16-28: Evolution of the overall velocity of the granular mass in the vertical direction.
Sheet of Figure 4
- Downslope Velocity Distribution: Along depth at time of t=0.5s,0.75s,1s,2s,3s,4s for Cases S1-S4. Each case includes three random scenarios.
Sheet of Figure 5
- Plots b-d:
- Average downslope velocity vs (Plot b) and normal velocity vn (Plot d) at different layers (Layer 1-3) for Cases S1 and S4 during the inclined-slope stage.
- Plots h-j:
- Evolution of downslope velocity vs (Plot h), normal velocity vn (Plot i), and angular velocity ω (Plot j) at the horizontal plane for Layers 1-3 in Cases S1 and S4.
Sheet of Figure 5e-5g
- Columns A-J: All grains' velocity values.
- Columns L-O: Grains with positive normal velocity values at t=1s.
- Columns Q-S: Velocity values of broken particles at t=1s.
- Columns U-W: Particle size distribution of grains with positive normal velocity.
Sheet of Figure 6
- Rows 1-20: Multi-layer stress distribution during the inclined-plane stage, including average normal stress (sigma_n) and shear stress (sigma_s).
- Rows 24-49: Multi-layer stress distribution during the horizontal-plane stage, including average normal stress (sigma_n) and shear stress (sigma_s).
Sheet of Figure 7
- Evolution of Velocities: Average downslope velocity, normal velocity, and angular velocity for particles of different sizes at times from 0.3s to 0.9s.
Sheet of Figure 8
- Columns A-D: Plot of particle angularity and particle size for Case S4 at t=1s.
- Columns F-K: Average downslope velocity vs, normal velocity vn, and angular velocity ω related to particle angularity for Case S4 at t=1s.
Sheet of Figure 9
- Average Translational Velocities: At measurement lines A (vx1) and B (vx2).
- Momentum Transfer Coefficient: η.
Sheet of Figure 10
- Rows 1-13: Evolution of vibrational granular temperature* *in layers L1-L3 for Cases S1 and S4.
- Rows 16-69: The Savage number along the traveling path at the horizontal-plane stage.
Sheet of Figure 11
- Interlayer Transmitting Coefficients: alpha_0 and alpha_r for Cases S1 and S4 at the inclined-plane and horizontal-plane stages.
- Columns A-I: Data for layers 1-2.
- Columns J-R: Data for layers 2-3.
- Columns S-AA: Data for layers 3-4.
- Bold Values: Data points in the figure.
Sheet of Figure 12
- Ratio of Cumulative Dissipated Energy Components to Total Potential Energy
- Ed: Fragmentation dissipation energy.
- Ek: Kinetic energy.
- Ef: Frictional dissipation energy.
- Ev: Viscous damping dissipation energy.
- Es: Strain energy.
Sheet of Table2
This sheet contains the raw data for calculating the equivalent coefficient and apparent coefficient of rock avalanches, including the breakage degree (Column B), the distance of the center of mass (Column C), and the height of the center of mass (Column D). The meanings of the other columns are indicated by the respective column headers.
Code/software
The numerical model was developed using ABAQUS, a commercial finite element analysis software. The specific version used was ABAQUS 2021. No additional scripts or code are included in this dataset.
This includes results of the numerical investigation into the fundamental aspects of progressive fragmentations within rock avalanches. This model is developed based on the platform of the commercial software ABAQUS. This link includes dataset of figures in this manuscript.