A model for the analysis of rapid landslide motion across three-dimensional terrain

2004 ◽  
Vol 41 (6) ◽  
pp. 1084-1097 ◽  
Author(s):  
Scott McDougall ◽  
Oldrich Hungr
Keyword(s):  
Debris Flows ◽  
Three Dimensional ◽  
Dynamic Modelling ◽  
Rock Avalanche ◽  
Stress Distributions ◽  
Flume Experiments ◽  
Mesh Distortion ◽  
Flow Slides ◽  
Particle Hydrodynamics ◽  
Smoothed Particle

A new numerical model for the dynamic analysis of rapid flow slides, debris flows, and avalanches has been developed. The model is an extension of an earlier algorithm and is implemented using a numerical method adapted from smoothed particle hydrodynamics. Its features include (i) the ability to simulate flow across complex three-dimensional terrain; (ii) the ability to allow nonhydrostatic and anisotropic internal stress distributions, coupled with strain changes through frictional relationships; (iii) the ability to simulate material entrainment; (iv) a choice of different rheological kernels, including frictional, plastic, viscous, Bingham, and Voellmy; (v) a meshless solution, which eliminates problems with mesh distortion during long displacements; and (vi) highly efficient and simple operation. The model has been tested by analysing a series of laboratory flume experiments with granular materials, both on straight and curved paths. The model is capable of accurately predicting the margins of various curving flows using a single set of input parameters. A preliminary analysis of a real rock avalanche case history is also included.Key words: landslides, debris flows, rock avalanches, runout analysis, dynamic modelling, numerical methods.

scholarly journals Depth-Integrated Two-Phase Modeling of Two Real Cases: A Comparison between r.avaflow and GeoFlow-SPH Codes

2021 ◽  
Vol 11 (12) ◽  
pp. 5751
Author(s):  
Seyed Ali Mousavi Tayebi ◽  
Saeid Moussavi Tayyebi ◽  
Manuel Pastor
Keyword(s):  
Rock Avalanche ◽  
Two Phase ◽  
Simulation Code ◽  
Simulation Tools ◽  
Mesh Free ◽  
Particle Hydrodynamics ◽  
Landslide Evolution ◽  
Smoothed Particle ◽  
Hazard And Risk ◽  
Comparison Of The Results

Due to the growing populations in areas at high risk of natural disasters, hazard and risk assessments of landslides have attracted significant attention from researchers worldwide. In order to assess potential risks and design possible countermeasures, it is necessary to have a better understanding of this phenomenon and its mechanism. As a result, the prediction of landslide evolution using continuum dynamic modeling implemented in advanced simulation tools is becoming more important. We analyzed a depth-integrated, two-phase model implemented in two different sets of code to stimulate rapid landslides, such as debris flows and rock avalanches. The first set of code, r.avaflow, represents a GIS-based computational framework and employs the NOC-TVD numerical scheme. The second set of code, GeoFlow-SPH, is based on the mesh-free numerical method of smoothed particle hydrodynamics (SPH) with the capability of describing pore pressure’s evolution along the vertical distribution of flowing mass. Two real cases of an Acheron rock avalanche and Sham Tseng San Tsuen debris flow were used with the best fit values of geotechnical parameters obtained in the prior modeling to investigate the capabilities of the sets of code. Comparison of the results evidenced that both sets of code were capable of properly reproducing the run-out distance, deposition thickness, and deposition shape in the benchmark exercises. However, the values of maximum propagation velocities and thickness were considerably different, suggesting that using more than one set of simulation code allows us to predict more accurately the possible scenarios and design more effective countermeasures.

scholarly journals Numerical Simulation of Non-Homogeneous Viscous Debris-Flows Based on the Smoothed Particle Hydrodynamics (SPH) Method

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2314 ◽  
Author(s):  
Shu Wang ◽  
Anping Shu ◽  
Matteo Rubinato ◽  
Mengyao Wang ◽  
Jiping Qin
Keyword(s):  
Debris Flow ◽  
Water Content ◽  
Smoothed Particle Hydrodynamics ◽  
Debris Flows ◽  
Sph Method ◽  
Particle Hydrodynamics ◽  
Sph Model ◽  
Smoothed Particle ◽  
The Impact ◽  
Kinetic And Potential Energies

Non-homogeneous viscous debris flows are characterized by high density, impact force and destructiveness, and the complexity of the materials they are made of. This has always made these flows challenging to simulate numerically, and to reproduce experimentally debris flow processes. In this study, the formation-movement process of non-homogeneous debris flow under three different soil configurations was simulated numerically by modifying the formulation of collision, friction, and yield stresses for the existing Smoothed Particle Hydrodynamics (SPH) method. The results obtained by applying this modification to the SPH model clearly demonstrated that the configuration where fine and coarse particles are fully mixed, with no specific layering, produces more fluctuations and instability of the debris flow. The kinetic and potential energies of the fluctuating particles calculated for each scenario have been shown to be affected by the water content by focusing on small local areas. Therefore, this study provides a better understanding and new insights regarding intermittent debris flows, and explains the impact of the water content on their formation and movement processes.

Smoothed Particle Hydrodynamics Simulations of Whole Blood in Three-Dimensional Shear Flow

2020 ◽  
Vol 17 (10) ◽  
pp. 2050009
Author(s):  
Sisi Tan ◽  
Mingze Xu
Keyword(s):  
Shear Flow ◽  
Smoothed Particle Hydrodynamics ◽  
Whole Blood ◽  
Blood Cells ◽  
White Blood Cells ◽  
Three Dimensional ◽  
Immersed Boundary ◽  
Particle Hydrodynamics ◽  
Sph Model ◽  
Smoothed Particle

Numerical modeling of whole blood still faces great challenges although significant progress has been achieved in recent decades, because of the large differences of physical and geometric properties among blood components, including red blood cells (RBCs), platelets (PLTs) and white blood cells (WBCs). In this work, we develop a three-dimensional (3D) smoothed particle hydrodynamics (SPH) model to study the whole blood in shear flow. The immersed boundary method (IBM) is used to deal with the interaction between the fluid and cells, which provides a possibility to model the RBCs, PLTs and WBCs simultaneously. The deformation of a small capsule, comparable to a PLT in size, is first examined to show the feasibility of SPH model for the PLTs’ behaviors. The motion of a single RBC in shear flow is then studied, and three typical modes, tank-treading, swinging and tumbling motions, are reproduced, which further confirm the reliability of the SPH model. After that, a simulation of the whole blood in shear flow is carried out, in which the margination trend is observed for both PLTs and WBC. This shows the capability of SPH model with IBM for the simulation of whole blood.

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