The Prediction of High-Speed Landslide Movement and Simulation of Generated Impulsive Wave by SPH Method

2011 ◽  
Vol 378-379 ◽  
pp. 418-422
Author(s):  
Ji Lun Miao ◽  
Jing Qiu Chen ◽  
Cen Wen
Keyword(s):  
High Speed ◽  
Limit Equilibrium ◽  
Soil Mass ◽  
Equilibrium Analysis ◽  
Sph Method ◽  
Limit Equilibrium Analysis ◽  
Particle Hydrodynamics ◽  
Sample Test ◽  
Smoothed Particle ◽  
Landslide Movement

A sliding block model is developed for predicting the runout of high-speed landslides, which couple with SPH method (Smoothed Particle Hydrodynamics) to simulate impulse wave. This model adopts the limit equilibrium analysis approach to simulate the whole travel process of the soil mass from the onset of the landslide. The submarine landslide produces highly unsteady and rapidly varied flows, so it was very complicated by fixed grid numerical simulations. The SPH method is a meshfree particle-based Lagrangian method. A sample test is given which shows the impulsive waves generated by high-speed landslide can be reproduced well.

scholarly journals Application of Limit Equilibrium Analysis and Numerical Modeling in a Case of Slope Instability

2020 ◽  
Vol 12 (21) ◽  
pp. 8870
Author(s):  
Fhatuwani Sengani ◽  
François Mulenga
Keyword(s):  
Numerical Simulation ◽  
Numerical Simulations ◽  
Limit Equilibrium ◽  
Slope Angle ◽  
Road Construction ◽  
Soil Mass ◽  
Slope Instability ◽  
Equilibrium Analysis ◽  
Limit Equilibrium Analysis ◽  
The Common

The application of limit equilibrium analysis and numerical simulation in case of slope instability is described. The purpose of the study was to use both limit equilibrium methods (LEMs) and numerical simulations (finite element method (FEM)) to understanding the common factor imposing the selected slope into slope instabilities. Field observations, toppling analysis, rotational analysis, and numerical simulations were performed. The results of the study showed that the selected unstable slopes were associated with the sliding types of toppling; it was observed that the slopes were governed by tension cracks and layered soil mass and dominated with approximately two joints sets throughout. The simulated factor of safety (FoS) of the slopes composed of clay soil was denoted to be prone to slope instability while others were categorized as moderately stable. The simulated FoS of the slopes correlated very well with the visual observations; however, it is anticipated that properties of soil mass and other characteristics of the slopes contributed largely to the simulated FoS. The sensitivity of the model was further tested by looking into the effect of the slope angle on the stability of the slope. The results of the simulations showed that the steeper the slope, the more they become prone to instability. Lastly, Phase 2 numerical simulation (FEM) showed that volumetric strain, shear stress, shear strain, total displacement, and σ1 and σ3 components of the slope increase with the stages of the road construction. It was concluded improper road construction, steepness of the slope, slope properties (soil types), and multiple geological features cutting across are the common mechanisms behind the slope instability.

Specific features of mathematical modeling of ceramic plates destruction under the influence of high-speed impactors

2021 ◽  
Author(s):  
A.V. Petukov ◽  
K.A. Grin
Keyword(s):  
Mathematical Modeling ◽  
High Speed ◽  
Plate Thickness ◽  
Vertex Angle ◽  
Courant Number ◽  
Sph Method ◽  
Viscosity Coefficients ◽  
Computational Mesh ◽  
Particle Hydrodynamics ◽  
Smoothed Particle

The paper examines the issues of mathematical modeling of ceramic armor panels’ penetration by high-speed cylindrical impactors. By means of the LS-DYNA software package, a corresponding numerical simulation methodology was developed by combining a chosen method, adjusted computational mesh cells size, appropriate Courant number, and values of linear and quadratic pseudo-viscosity coefficients. The results compared with experimental data show that Lagrangian and Eulerian numerical methods, unlike the SPH method (Smoothed Particle Hydrodynamics), improperly reproduce the process of the shock wave disintegration into an elastic precursor and a plastic wave. In addition, the common size of conical fractions dislodging from the ceramic plates was determined and the influence of the scale effect on the ceramics damage patterns was shown: an increase in the absolute value of the plate thickness leads to the increase in the dislodging cone semi-vertex angle.

Numerical Simulation of High Speed Water Jet Erosion of Sand Bed Based on SPH

2014 ◽  
Vol 641-642 ◽  
pp. 304-308
Author(s):  
Fu Sheng Ni ◽  
De Yi Zhang ◽  
Hui Wang ◽  
Lei Gu
Keyword(s):  
High Speed ◽  
Pressure Field ◽  
Water Jet ◽  
Target Distance ◽  
Sph Method ◽  
Simulation Process ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Jet Velocity ◽  
Key Techniques

Water jet technology is widely used in dredging engineering. Since there will be large deformation of sand bed during erosion by water jet, the calculation mesh will be distorted seriously and lead to simulation failure. In order to solve the problem, the Smoothed Particle Hydrodynamics (SPH) method was used to simulate the dynamic process of high speed water jet erosion of sand bed. The simulation process and key techniques were discussed, the effect of water jet velocity and water jet target distance on the depth of eroded pit was studied. The results show that SPH could describe the process intuitively and the evolution of particle velocity field and sand bed pressure field could be shown clearly. The depth of the pit varies with time linearly. The decrease of water jet target distance and the increase of the water jet velocity deepen the eroded pit.

Numerical Simulation of Water Entry with Improved SPH Method

2018 ◽  
Vol 16 (02) ◽  
pp. 1846004 ◽  
Author(s):  
J. R. Shao ◽  
Y. Yang ◽  
H. F. Gong ◽  
M. B. Liu
Keyword(s):  
High Speed ◽  
Moving Objects ◽  
Treatment Algorithm ◽  
Water Entry ◽  
Sph Method ◽  
Moving Interfaces ◽  
Particle Hydrodynamics ◽  
Sph Model ◽  
Smoothed Particle ◽  
Interface Treatment

Water entry problems are very common in engineering and sciences. When objects move with relatively high speed, bubble cavities will be generated, and the behavior of moving objects will also be affected conversely. In this paper, the water entry problems are studied using smoothed particle hydrodynamics (SPH) method, which has special advantages in modeling free surfaces, moving interfaces. First, an improved fluid–solid interface treatment algorithm is presented, whose effectiveness is validated by a water entry of a buoyant cylinder. Then the water entry with different velocities and directions are researched. It is found that the velocities and angles of the moving objects will affect the movement of the object greatly, and the SPH model can give optimal predication of these corresponding conditions.

A sliding block model for the runout prediction of high-speed landslides

2001 ◽  
Vol 38 (2) ◽  
pp. 217-226 ◽  
Author(s):  
Tiande Miao ◽  
Zhongyu Liu ◽  
Yonghong Niu ◽  
Chongwu Ma
Keyword(s):  
High Speed ◽  
Limit Equilibrium ◽  
Soil Mass ◽  
Travel Speed ◽  
Equilibrium Analysis ◽  
Block Model ◽  
Initial Stress State ◽  
Runout Distance ◽  
Slide Mass ◽  
Sliding Block Model

A sliding block model is developed for predicting the runout of high-speed slide-like landslides, based on the analysis of the dynamic mechanism of high-speed landslides. This model adopts the limit equilibrium analysis approach and incorporates mass dynamics and soil deformation into the calculation of soil movements. The critical state is considered as the initial stress state, and the interslice forces are obtained considering the equivalence of deformation energy. It is possible, applying this model, to simulate the whole travel process of the soil mass from the onset of the landslide and to predict the travel speed of the soil mass and the hazard area of the landslide. Application of the model to the Sale Mountain landslide and the Tianshui Forging Machine Factory landslide in China gives reasonable results in comparison to the field observations. The calculated results illustrate that (i) the fundamental causes of the high speed are the decline of the resultant friction force during sliding and the rapid and large fall of the centre of gravity of the back part of the slide mass; and (ii) the slide mass generally moves as a whole during the middle sliding stage, and the front part of the slide mass is often in a state of relaxation, even extension, at the end of the movement.Key words: high-speed landslides, dynamic analysis, runout distance, block model.

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.

Numerical investigation of anguilliform locomotion by the SPH method

2019 ◽  
Vol 30 (1) ◽  
pp. 328-346 ◽  
Author(s):  
Amin Rahmat ◽  
Hossein Nasiri ◽  
Marjan Goodarzi ◽  
Ehsan Heidaryan
Keyword(s):  
Drag Coefficient ◽  
Numerical Investigation ◽  
Sph Method ◽  
Content Type ◽  
Aquatic Locomotion ◽  
Wide Range ◽  
Particle Hydrodynamics ◽  
Dummy Particles ◽  
Smoothed Particle ◽  
Sph Algorithm

Purpose This paper aims to introduce a numerical investigation of aquatic locomotion using the smoothed particle hydrodynamics (SPH) method. Design/methodology/approach To model this problem, a simple improved SPH algorithm is presented that can handle complex geometries using updatable dummy particles. The computational code is validated by solving the flow over a two-dimensional cylinder and comparing its drag coefficient for two different Reynolds numbers with those in the literature. Findings Additionally, the drag coefficient and vortices created behind the aquatic swimmer are quantitatively and qualitatively compared with available credential data. Afterward, the flow over an aquatic swimmer is simulated for a wide range of Reynolds and Strouhal numbers, as well as for the amplitude envelope. Moreover, comprehensive discussions on drag coefficient and vorticity patterns behind the aquatic are made. Originality/value It is found that by increasing both Reynolds and Strouhal numbers separately, the anguilliform motion approaches the self-propulsion condition; however, the vortices show different pattern with these increments.

Progressive failure of the Carsington Dam: a numerical study

1992 ◽  
Vol 29 (6) ◽  
pp. 971-988 ◽  
Author(s):  
Z. Chen ◽  
N. R. Morgenstern ◽  
D. H. Chan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Factor Of Safety ◽  
Progressive Failure ◽  
Limit Equilibrium ◽  
Equilibrium Analysis ◽  
Element Analysis ◽  
Limit Equilibrium Analysis ◽  
The Finite Element Analysis ◽  
Yellow Clay

The mechanism of progressive failure is well understood as one which involves nonuniform straining of a strain-weakening material. Traditional limit equilibrium analysis cannot be used alone to obtain a rational solution for progressive failure problems because the deformation of the structure must be taken into account in the analysis. The failure of the Carsington Dam during construction in 1984 has been attributed to progressive failure of the underlying yellow clay and the dam core materials. The dam was monitored extensively prior to failure, and an elaborate geotechnical investigation was undertaken after failure. The limit equilibrium analysis indicated that the factors of safety were over 1.4 using peak strength of intact clay material or 1.2 based on reduced strength accounting for preshearing of the yellow clay layer. Factors of safety were found to be less than unity if residual strengths were used. The actual factor of safety at failure was, of course, equal to one. By using the finite element analysis with strain-weakening models, the extent and degree of weakening along the potential slip surface were calculated. The calculated shear strength was then used in the limit equilibrium analysis, and the factor of safety was found to be 1.05, which is very close to the actual value of 1.0. More importantly, the mechanism of failure and the initiation and propagation of the shear zones were captured in the finite element analysis. It was also found that accounting explicitly for pore-water pressure effects using the effective stress approach in the finite element and limit equilibrium analyses provides more realistic simulations of the failure process of the structure than analyses based on total stresses. Key words : progressive failure, strain softening, finite element analysis, dams.

Sign in / Sign up

Export Citation Format

Share Document