Visual Simulation of Soil-Structure Destruction with Seepage Flows

2021 ◽  
Vol 4 (3) ◽  
pp. 1-18
Author(s):  
Xu Wang ◽  
Makoto Fujisawa ◽  
Masahiko Mikawa
Keyword(s):  
Soil Structure ◽  
Water Saturation ◽  
Seepage Flow ◽  
Momentum Exchange ◽  
Visual Effects ◽  
Seepage Rate ◽  
Capillary Model ◽  
Seepage Flows ◽  
Dam Breaking ◽  
Soil And Water

This paper introduces a method for simulating soil-structure coupling with water, which involves a series of visual effects, including wet granular materials, seepage flows, capillary action between grains, and dam breaking simulation. We develop a seepage flow based SPH-DEM framework to handle soil and water particles interactions through a momentum exchange term. In this framework, water is seen as a seepage flow through porous media by Darcy's law; the seepage rate and the soil permeability are manipulated according to drag coefficient and soil porosity. A water saturation-based capillary model is used to capture various soil behaviors such as sandy soil and clay soil. Furthermore, the capillary model can dynamically adjust liquid bridge forces induced by surface tension between soil particles. The adhesion model describes the attraction ability between soil surfaces and water particles to achieve various visual effects for soil and water. Lastly, this framework can capture the complicated dam-breaking scenarios caused by overtopping flow or internal seepage erosion that are challenging to simulate.

scholarly journals Description and Application of A Model of Seepage under A Weir Including Mechanical Clogging

2014 ◽  
Vol 21 (1) ◽  
pp. 3-9
Author(s):  
Zbigniew Sroka ◽  
Zbigniew Walczak ◽  
Bogdan Wosiewicz
Keyword(s):  
Seepage Flow ◽  
Euler Method ◽  
The Finite Element Method ◽  
Seepage Velocity ◽  
Discrete Form ◽  
Upstream Site ◽  
Seepage Rate ◽  
One Dimensional ◽  
Hydraulic Gradients ◽  
Layer Flow

Abstract The paper discusses seepage flow under a damming structure (a weir) in view of mechanical clogging in a thin layer at the upstream site. It was assumed that in this layer flow may be treated as one-dimensional (perpendicular to the layer), while elsewhere flow was modelled as two-dimensional. The solution in both zones was obtained in the discrete form using the finite element method and the Euler method. The effect of the clogging layer on seepage flow was modelled using the third kind boundary condition. Seepage parameters in the clogging layer were estimated based on laboratory tests conducted by Skolasińska [2006]. Typical problem was taken to provide simulation and indicate how clogging affects the seepage rate and other parameters of the flow. Results showed that clogging at the upstream site has a significant effect on the distribution of seepage velocity and hydraulic gradients. The flow underneath the structure decreases with time, but these changes are relatively slow.

scholarly journals Seepage Behavior of Earth Dams Considering Rainfall Effects

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Jong-Wook Lee ◽  
Jiseong Kim ◽  
Gi-Chun Kang
Keyword(s):  
Monsoon Season ◽  
Seepage Flow ◽  
Water Levels ◽  
Annual Rainfall ◽  
Seepage Water ◽  
Earth Dams ◽  
Reservoir Water ◽  
Seepage Rate ◽  
Steady State Condition ◽  
Rock Fill

More than 60% of annual rainfall in Korea is concentrated during the monsoon season from June to August because of the climate characteristics of East Asia. In general, reservoir water levels sharply rise during this period and rock-fill dams are exposed to various types of damages such as soil erosion and piping related to seepage problems. However, the detection of seepage problems is generally more difficult because rainfall directly flows into a V-notch weir according to a downstream shell in which seepage rates can be measured downstream. In this paper, rainfall is filtered out from the measured seepage rates to evaluate the effects of rainfall by using a digital filtering method for two large rock-fill dams (Dams A and B). Seepage behavior for these two large rock-fill dams was estimated as a steady-state condition. It has been proven that with the application of a digital filter which filters out rainfall-induced infiltration into a downstream shell from a measured seepage flow would make analyzing the seepage behavior of dams more effective. This also shows that consideration for any rainfall effect on the seepage behavior of earth dams is very important. The seepage rate of Dam A was not significantly affected by rainfall because the seepage water was collected inside the dam body and was transferred to a V-notch weir located downstream from the dam through a steel pipe. On the contrary, the seepage rate of Dam B was greatly influenced by rainfall in the rainy season. Also, the permeability of the core zones for Dams A and B was estimated at 8.5 × 10−5 cm/sec and 2.7 × 10−5 cm/sec, respectively, by a simplified method.

Anisotropy Properties of Turbulence in Flow Over Seepage Bed

2021 ◽  
Author(s):  
Anurag Sharma ◽  
Bimlesh Kumar
Keyword(s):  
Reynolds Stress ◽  
Isotropic Turbulence ◽  
Outer Region ◽  
Seepage Flow ◽  
Invariant Function ◽  
Data Sets ◽  
Flow Depth ◽  
Seepage Flows ◽  
Two Component ◽  
Anisotropy Tensor

Abstract The present study analyses the Reynolds stress anisotropy in the non-uniform sediment beds under the condition of no seepage and downward seepage flow. The results show the estimation of the deviation measure from the isotropic turbulence in view of Reynolds stress tensor for turbulent flow in the presence of seepage through the channel bed. The investigation presents the Lumley triangle for flow turbulence, Eigen values, and the invariant functions for the whole flow depth subjected to no seepage and seepage beds. The longitudinal profile of anisotropy tensor within the near-bed zone for seepage flow provides the higher anisotropic stream than those of no seepage flow, while the remaining (transverse and vertical) profiles of anisotropy tensor in the vicinity of bed for seepage flows provides lower anisotropic stream. The anisotropic invariant maps show the near bed anisotropy inclining to be a two-component isotropy subjected to no seepage and seepage flow. With the increase in vertical distance from bed surface that is close to the water surface, the data sets of anisotropic invariant maps for no seepage and seepage flows show a trend of one-component isotropy, while it has an affinity to develop a three-component isotropy in the vicinity of mid zone of the flow depth. Invariant function data sets present a well two-component isotropy in the near bed region of flow and a quasi-three component isotropy in the outer region of flow for seepage flows as compared to no seepage flow.

A novel hybrid meshless method for seepage flows in non-homogeneous and anisotropic soils

2018 ◽  
Vol 35 (2) ◽  
pp. 867-886
Author(s):  
Mohammad Hajiazizi ◽  
Adel Graili
Keyword(s):  
Interpolation Method ◽  
Seepage Flow ◽  
Delta Function ◽  
Sharp Corner ◽  
Content Type ◽  
Seepage Flows ◽  
Analytical Scheme ◽  
Point Interpolation Method ◽  
Singularity Point ◽  
Anisotropic Soil

Purpose The purpose of this paper is to extend the scaled boundary radial point interpolation method (SBRPIM), as a novel semi-analytical scheme, to the analysis of the steady state confined seepage flows. Design/methodology/approach This method combines the advantages of the scaled boundary finite element method and the BRPIM. In this method, only boundary nodes are used, no fundamental solution of the problem is required, and as the shape functions constructed based on the RPIM satisfy the Kronecker delta function property, the boundary conditions of problems can be imposed accurately and easily. Findings Three numerical examples, including seepage flow through homogeneous and non-homogeneous soils, are analyzed in this paper. Comparing the flow net obtained by SBRPIM and other numerical methods confirms the ability of the proposed method in analyzing seepage flows. In addition, in these examples, the accuracy of the SBRPIM in modeling the velocity singularity at a sharp corner is illustrated. SBRPIM accurately models the singularity point in non-homogeneous and anisotropic soil. Originality/value SBRPIM method is a simple effective tool for analyzing various kinds of engineering problems. It is easy to implement for modeling the velocity singularity at a sharp corner. The proposed method accurately models the singularity point in non-homogeneous and anisotropic soil.

Simulation of Seepage Flow in Earth Dam with a Free Surface

2012 ◽  
Vol 433-440 ◽  
pp. 1465-1469
Author(s):  
Wen Li Wei ◽  
Hong Zhao ◽  
Pei Zhang ◽  
Y.I. Liu
Keyword(s):  
Mathematical Model ◽  
Seepage Flow ◽  
Earth Dam ◽  
Matrix Equations ◽  
The Finite Element Method ◽  
Curvilinear Boundary ◽  
Seepage Flows ◽  
Large Matrix ◽  
Physical Laws ◽  
The Mathematical Model

The technique of curvilinear boundary-fitted coordinate system is used for the mathematical model of pressure underground seepage flow and the boundary conditions and the method of solving the transformed equations have been presented. The computing example shows that the computed hydraulic parameters conform to the physical laws. Compared with the finite element method, the presented method need not solve the large matrix equations, and the computer memories and the time for computing are less. The mathematical model is effective for numerical solution of seepage flows with complicated boundaries, and can be used in practice hydraulic engineering.

Image-based model quantification of pore-scale nitrogen diffusion and potential microbial ‘dead zones’ induced by fertilization application

2020 ◽  
Author(s):  
Siul Ruiz ◽  
Daniel McKay Fletcher ◽  
Andrea Boghi ◽  
Katherine Williams ◽  
Simon Duncan ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Microbial Communities ◽  
Microbial Activity ◽  
Soil Solution ◽  
Soil Structure ◽  
Water Saturation ◽  
Soil Microbial Communities ◽  
Scale Model ◽  
Organic N ◽  
Pore Scale

<div> <p>Soil microbial communities contribute many ecosystem services including soil structure maintenance, crop synergy, and carbon sequestration. However, it is not fully understood how the health of microbial communities is effected by fertilization at the pore scale. This study investigates the nature of nitrogen (N) transport and reactions at the soil pore scale in order to better understand the influence of soil structure and moisture content on microbial community health. Using X-ray Computed Tomography (XRCT) scans, we reconstructed a microscale description of a dry soil-pore geometry as a computational mesh. Solving two-phase water/air models produced pore-scale water distributions at 15, 30 and 70% water-filled pore volume. The model considers ammonium (NH<sub>4</sub><sup>+</sup>), nitrate (NO<sub>3</sub><sup>-</sup>) and dissolved organic N (DON), and includes N immobilization, ammonification and nitrification processes, as well as diffusion in soil-solution. We simulated the dissolution of a fertilizer pellet and a pore scale N cycle at the three different water saturation conditions. To aid interpretation of the model results, microbial activity at a range of N concentrations was quantified experimentally using labelled C to infer microbial activity based on CO<sub>2</sub> respiration measurements in bulk soil. The pore-scale model showed that the diffusion and concentration of N in water films is critically dependent upon soil moisture and N species. We predicted that the maximum NH<sub>4</sub><sup>+</sup> and NO<sub>3</sub><sup>-</sup> concentrations in soil solution around the pellet under low water saturation conditions (15%) are in the order of 1x10<sup>3</sup> and 1x10<sup>4</sup> mol m<sup>-3</sup> respectively (1-10 M), and under higher water saturation conditions (70%) where on the order of 2x10<sup>2</sup> and 1x10<sup>3</sup> mol m<sup>-3</sup>, respectively (0.1-1 M). Supporting experimental evidence regarding microbial respiration suggests that these concentrations at the pore-scale would be sufficient to reduce microbial activity in the zone immediately around the fertilizer pellet (ranging from 0.9 to 3.8 mm depending on soil moisture status), causing a major loss of soil biological activity by up to 90%. This model demonstrates the importance of pore-scale processes in regulating N movement in soil with special capability to predict the effects of fertilizers on rhizosphere-scale processes and the root microbiome.</p> </div>

Numerical Solution of Pressure Underground Seepage Flow Using a Technique of Curvilinear Boundary-Fitted Coordinates

2014 ◽  
Vol 501-504 ◽  
pp. 1878-1882
Author(s):  
Hong Zhao ◽  
Wen Li Wei
Keyword(s):  
Mathematical Model ◽  
Numerical Solution ◽  
Seepage Flow ◽  
Matrix Equations ◽  
The Finite Element Method ◽  
Curvilinear Boundary ◽  
Seepage Flows ◽  
Large Matrix ◽  
Physical Laws ◽  
The Mathematical Model

The technique of curvilinear boundary-fitted coordinate system is used for the mathematical model of pressure underground seepage flow and the boundary conditions and the method of solving the transformed equations have been presented. The computing example shows that the computed hydraulic parameters conform to the physical laws. Compared with the finite element method, the presented method need not solve the large matrix equations, and the computer memories and the time for computing are less. The mathematical model is effective for numerical solution of pressure underground seepage flows with complicated boundaries, and can be used in practice hydraulic engineering. Keywords-curvilinear boundary-fitted coordinate, pressure underground seepage flow, mathematical model

A simplified method to estimate saturated and unsaturated seepage through dikes under steady-state conditions

2001 ◽  
Vol 38 (6) ◽  
pp. 1321-1328 ◽  
Author(s):  
Robert P Chapuis ◽  
Michel Aubertin
Keyword(s):  
Industrial Wastewater ◽  
Unsaturated Flow ◽  
Seepage Flow ◽  
Seepage Rate ◽  
The Core ◽  
Downstream Slope ◽  
Dimensional Finite Element ◽  
Filter Layer ◽  
Seepage Face ◽  
Unsaturated Seepage

The seepage rate through homogeneous or zoned dikes includes saturated and unsaturated flow. The latter is often neglected but should be considered to obtain the positions of the water table and the seepage face that may develop either on the downstream slope of a homogeneous dike or within the filter layer behind the core of a zoned dike. Different dikes with heights of 5, 10, 20, and 50 m have been analyzed numerically with a two-dimensional finite element code. The cases investigated include the most frequent types of small dikes designed to retain municipal or industrial wastewater. Solutions are proposed to solve numerically two difficulties related to the representation of saturated and unsaturated physical flow conditions. One difficulty is treating a downstream seepage face. The other is treating the passage of water from the core into a draining layer. The paper presents simple expressions to predict the total (saturated and unsaturated) seepage flow rate through a dike and discusses precautions to be taken.Key words: dams, dikes, seepage, saturated soil, unsaturated soil, numerical modeling.

scholarly journals Quality No-tillage System: The Importance of the Use of Cover Species in Reducing Compaction and Soil and Water Losses Due to Erosion

2019 ◽  
Vol 11 (2) ◽  
pp. 263
Author(s):  
Bruna de Villa ◽  
Deonir Secco ◽  
Luciene Kazue Tokura ◽  
Aracéli Ciotti de Marins ◽  
Pablo Chang ◽  
...  
Keyword(s):  
Surface Runoff ◽  
Soil Structure ◽  
Rainfall Intensity ◽  
Quality Management System ◽  
Water Infiltration ◽  
Effective Control ◽  
No Tillage ◽  
Water Losses ◽  
Tillage System ◽  
Soil And Water

Water and soil losses due to surface runoff depend on rainfall intensity and periods, vegetation cover, slope, and ramp length, in addition to conservation practices. The implementation of a quality planting system for the effective control of erosion while avoiding the disintegration of the soil structure by the direct impact of dropping is of paramount importance. Nevertheless, the current no-tillage system has led to the emergence of compacted layers in the soil, which reduce water infiltration, favoring surface runoff. Thus, it is necessary to optimize the use of soil cover species, aiming at reducing compaction and, subsequently, losses of water and soil that flow superficially. The purpose of this study is to highlight the importance of using a quality management system to reduce soil and water losses due to erosion caused by compaction. Furthermore, it is hoped that the study may contribute to the guidance of the best use and management of the soil for farmers.

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