Numerical simulation of uneven settlement of municipal solid waste landfill by FLAC 3D

2021 ◽  
pp. 0734242X2110667
Author(s):  
Hongjun Sun ◽  
Erchong Gao ◽  
Aipeng Zhou
Keyword(s):  
Numerical Simulation ◽  
Landfill Site ◽  
Three Dimensions ◽  
Slope Position ◽  
Soil Parameters ◽  
Lagrangian Analysis ◽  
Maximum Angle ◽  
Maximum Elevation ◽  
Maximum Subsidence ◽  
Flac 3D

After the landfill site is sealed, the uneven settlement is related to the safety of reutilisation of the site, and it is critical to calculate the uneven settlement of the site without error. In this article, the soil parameter of garbage body was changed with biodegradation. Fast Lagrangian Analysis of Continua in three dimensions (FLAC 3D) numerical simulation was applied to the settlement of the landfill site closure. In calculating the settlement of landfill, the soil parameters of landfill with age were obtained by field drilling experiments. The parameters can reflect the characteristics of soil organic matter in different biodegradation stages. Finally, the uneven settlement within 20 years of the closure period was obtained by the numerical simulation taking Jinzhou Nanshan landfill as an example. The results show that the settlement with the age increases gradually, but the rate will be more and more moderate, and the maximum subsidence value in the sealing field after 20 years will be 9.11 m, 15.71% of the maximum elevation. Around the landfill slope position of uneven settlement rate is bigger, and the maximum angle of uneven settlement is up to 45°. But the middle position is small, which is close to 0°.

Numerical Simulation of Structure Dynamic Response for Civil Architecture under Mining Blasting Vibration

2011 ◽  
Vol 255-260 ◽  
pp. 3817-3821
Author(s):  
Zhi Yu Zhang ◽  
Long Fa Luan ◽  
Jian Bin Xie
Keyword(s):  
Dynamic Response ◽  
Mechanical Model ◽  
Three Dimensions ◽  
Blasting Vibration ◽  
Structural Stress ◽  
Structure Model ◽  
The Finite Element Method ◽  
Lagrangian Analysis ◽  
Geological Conditions ◽  
Flac 3D

According to the geological conditions of mine and mine’s surrounding construction, the geological mechanical model of explosion area and the structure model of surrounding civil architecture were established. Based on the monitoring blasting vibration result of mining explosion process, the dynamic response character and structural stress of surrounding civil architecture which have been caused by blasting vibration of mining were studied by means of the Finite Element Method (FEM) and the method of fast Lagrangian analysis of continua three dimensions (FLAC 3D). The results show that calculated results coincide with the monitor results collectively, and the influence caused by blasting vibration on the stress and strains of civil architecture is smaller. But at the civil architecture roof, the transient amplification acceleration caused by blasting is 25%.

Numerical Simulation on the Stress Distribution of Thin Seam Containing Iron-Sulfide-Cores

2013 ◽  
Vol 316-317 ◽  
pp. 799-802 ◽  
Author(s):  
Yun Liang Tan ◽  
Wei Min Li ◽  
Su Jun Miao ◽  
Ping Wei ◽  
Tong Bin Zhao ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Plastic Zone ◽  
Iron Sulfide ◽  
Mining Area ◽  
Three Dimensions ◽  
Mine Pressure ◽  
Lagrangian Analysis ◽  
Working Face ◽  
Stress Curve ◽  
Thin Seam

Fast Lagrangian Analysis of Continua in three Dimensions was adapted to establish numerical model of thin seam with Iron-sulfide-cores, based on the conditions of thin seam in Yanzhou Mining Area, and the influence of existing cores or not, cores in different positions, cores contents on mine pressure was studied. The results showed that, stress concentration and plastic zone is more easily to be formed in the coal around cores. When there are cores in coal, the bahaviors of abutment stress foreside the working face have no significant differences, the abutment stress curve is fluctuation and width or range of plastic zone little changed, but the boundary of plastic zone is fuzzy and radial. The boundary of plastic zone has some difference with the increasing of cores contents, but other macroscopic mine pressure behaviors has no significant differences. It is helpful to understand spalling mechanism of iron-sulfide-cores in thin seam.

Hydraulic Characteristics of the New Type Bulb Turbine With Micro-Head

2013 ◽  
Author(s):  
Lingyu Li ◽  
Yuan Zheng ◽  
Daqing Zhou ◽  
Zihao Mi
Keyword(s):  
Numerical Simulation ◽  
Cfd Simulation ◽  
Guide Vane ◽  
Three Dimensional ◽  
Flow Distribution ◽  
Three Dimensions ◽  
Guide Vanes ◽  
Runner Blade ◽  
Cfd Method ◽  
Bulb Turbine

The head of low-head hydropower stations is generally higher than 2.5m in the world, while micro-head hydropower resources which head is less than 2.5m are also very rich. In the paper, three-dimensional CFD method has been used to simulate flow passage of the micro-head bulb turbine. The design head and unit flow of the turbine was 1m and 3m3/s respectively. With the numerical simulation, the bulb turbine is researched by analyzing external characteristics of the bulb turbine, flow distribution before the runner, pressure distribution of the runner blade surface, and flow distribution of the outlet conduit under three different schemes. The turbine in second scheme was test by manufactured into a physical model. According to the results of numerical simulation and model test, bulb turbine with no guide vane in second scheme has simpler structure, lower cost, and better flow capacity than first scheme, which has traditional multi-guide vanes. Meanwhile, efficiency of second scheme has just little decrease. The results of three dimensions CFD simulation and test results agree well in second scheme, and higher efficiency is up to 77% which has a wider area with the head of 1m. The curved supports in third scheme are combined guide vanes to the fixed supports based on 2nd scheme. By the water circulations flowing along the curved supports which improve energy transformation ability of the runner, the efficiency of the turbine in third scheme is up to 82.6%. Third scheme, which has simpler structure and best performance, is appropriate for the development and utilization of micro-head hydropower resources in plains and oceans.

scholarly journals Global ionospheric models in three dimensions from GPS measurements: Numerical simulation

2000 ◽  
Vol 39 (1) ◽  
pp. 21-27
Author(s):  
Amali Meza ◽  
Claudio Brunini ◽  
Alfred Kleusberg
Keyword(s):  
Numerical Simulation ◽  
Three Dimensions ◽  
Gps Measurements ◽  
Atmospheric Research ◽  
Ionospheric Models

Gracias a las observaciones GPS en doble - frecuencia de receptores distribuidos uniformemente sobre la superficie terrestre es posible hacer un análisis de la ionosfera como puede verse en los trabajos de Mannucci A. et al., 1993; Beutler G., 1995 y Brunini C. et al., 1997 entre otros. Este análisis consiste básicamente en el modelado de las variaciones del contenido total de electrones en función de 2 coordenadas que bien pueden ser la latitud y la longitud en un sistema sol fijo. Estos modelos asumen que la ionosfera puede representarse por una capa esférica de espesor despreciable, situada a una determinada altura (entre los 300 y 400 km), donde se concentra la totalidad de los electrones libres. Para modelar la distribución espacial de la concentración total de electrones en la delgada capa, se han utilizado series de Taylor en dos dimensiones o armónicos esféricos entre otros. En abril de 1995, gracias al lanzamiento de la misión GPS-MET, se pudo hacer realidad la obtención de observaciones GPS desde un receptor en el espacio. GPS-MET es un experimento dirigido por el UCAR (University Corporation of Atmospheric Research), cuyo objetivo es el sondeo de la atmósfera terrestre mediante observaciones GPS colectadas por un receptor de alto rendimiento situado a bordo del satélite MicroLab I (MLI). Este satélite describe una órbita circular a 730 km de altura (LEO=Low Elevation Orbit), con una inclinación de 60°. Las observaciones colectadas por este receptor están disponibles vía ftp en una base de datos administrada por el UCAR. Este satélite de baja altura con receptor GPS de doble frecuencia nos brinda la posibilidad de contar con señales GPS que atraviesan la ionosfera a diferentes alturas. Este trabajo no apunta a discutir un modelo ionosférico en sí mismo, sino más bien a analizar las posibilidades de utilizar mediciones GPS para extraer información sobre el comportamiento vertical de la densidad electrónica, basadas en un modelo medio y global. En este trabajo emplearemos simulaciones numéricas con el objetivo de analizar si las observaciones del Microlab I son suficientemente sensibles a las variaciones en altura de la ionosfera. Afortunadamente y pese a la limitación en la geometría del problema, ya que sólo contamos con un satélite de órbita fija, se concluye que el receptor espacial nos brinda información fundamental para el modelado en altura de la densidad de electrones.

Numerical Simulation of Multibody Systems With Time Dependant Structure

1993 ◽  
Author(s):  
Pierre Joli ◽  
Madeleine Pascal ◽  
René Gibert
Keyword(s):  
Numerical Simulation ◽  
Multibody Systems ◽  
Computational Algorithm ◽  
Rigid Bodies ◽  
Three Dimensions ◽  
Integration Step ◽  
General Systems ◽  
Articulated Systems ◽  
Jump Velocity ◽  
Assembly Tasks

Abstract Current dynamic simulation programs are able to calculate the continuous motions of articulated systems or more general systems of rigid bodies in the absence of contact between members of the system or between the system and its environment. Some are able to simulate the effects of isolated contacts and impacts but none are able to simulate the motion with unrestricted multiple concurrent contacts. However, in special robotic programs such as robots performing assembly tasks or walking, it would be very interesting to simulate appropriate commands before implementing them on the robots. This paper develops intrinsic problems of collision to produce an efficient computational algorithm. This algorithm handles the detection of collision in three dimensions, the reduction of the integration step in order to avoid interpenetration between the bodies before impact, the jump velocity caused by a new collision and indicator magnitudes which determine the addition or deletion of constraints.

Assessment of Guar Gum Biopolymer Treatment toward Mitigation of Desiccation Cracking on Slopes Built with Expansive Soils

2017 ◽  
Vol 2657 (1) ◽  
pp. 78-88 ◽  
Author(s):  
Raju Acharya ◽  
Aravind Pedarla ◽  
Tejo V. Bheemasetti ◽  
Anand J. Puppala
Keyword(s):  
Factor Of Safety ◽  
Slope Failure ◽  
Soil Stabilization ◽  
Guar Gum ◽  
Expansive Soils ◽  
Environmental Benefits ◽  
Three Dimensions ◽  
Slope Failures ◽  
Lagrangian Analysis ◽  
Desiccation Cracking

Expansive soil embankments are prone to shallow slope failures caused by associated swell–shrink movements. Previous studies have confirmed that seasonal changes and corresponding volumetric changes are responsible for desiccation cracking, which is a major factor behind shallow slope failures of highway embankments. For the past few years, soil stabilization proved to be an effective way to mitigate the swell–shrink property of expansive clays. The current study addresses the feasibility of guar gum biopolymer in mitigating the swell–shrink behavior of clays and in turn making it possible to adopt them as stable geomaterials. The sustainable benefits of biopolymers far exceed the environmental benefits from conventional stabilizers that contractors typically use. This paper presents a comprehensive laboratory study, followed by finite difference modeling analysis, on biopolymeric guar gum–remediated expansive soils collected from shallow slope failure-prone areas. For this study, two dam locations, at Grapevine Lake and Joe Pool Lake, Texas, that were originally constructed with expansive soils, were considered. The engineering performance of biopolymer-treated soils was evaluated and an optimum dosage was recommended for mitigating desiccation cracking at the test sites. Slope stability analyses were conducted using Fast Lagrangian Analysis of Continua in Three Dimensions software by adopting laboratory-determined strength parameters to determine the range of the factor of safety for the slopes. The variation of the factor of safety computed with the inclusion of enhanced engineering parameters from guar gum treatments revealed the advantages of adopting this treatment.

scholarly journals The influence law of grouser shape on soil slide sinkage when tracked vehicle travels on soft road

2019 ◽  
Vol 234 (1) ◽  
pp. 225-237
Author(s):  
Jian He ◽  
Dalin Wu ◽  
Jisheng Ma ◽  
Hongkai Wang ◽  
Yuliang Yang
Keyword(s):  
Numerical Simulation ◽  
System Dynamics ◽  
Simulation Model ◽  
Multibody System ◽  
Multibody System Dynamics ◽  
Shear Displacement ◽  
Soil Parameters ◽  
Tracked Vehicle ◽  
Physical Test ◽  
Tracked Vehicles

The influence law of a tracked vehicle grouser shape on the soil slide sinkage was investigated in this study via the numerical simulations and physical tests. A finite element model was built using the plastic incremental theory and generalized Hokker’s law, while constitutive soil parameters were obtained via triaxial test. The numerical simulation model was verified by physical test results. Based on the verified numerical simulation model, the influence law of the tracked vehicle grouser shape on the soil slide sinkage was determined. The results show that (1) shear displacement in the lateral direction can increase the soil sinkage in the vertical direction, which is referred to as the “slide sinkage”; (2) there is a linear relationship between the slide sinkage and the shear displacement; (3) the grouser width and height have a positive influence on the amount of slide sinkage. Under the same load, an increase in grouser width and height will cause an increase in the soil slide sinkage. Grouser thickness and pitch have a negative influence on the slide sinkage, and under the same load, increased grouser width and height cause a reduction in the soil slide sinkage. Grouser angle characteristics have no significant effect on the soil sinkage. The application of the slide sinkage in tracked vehicles traveling on soft roads was investigated in multibody system dynamics analysis software Recurdyn to confirm these observations. The results presented in this paper may provide a workable reference for the analysis of tracked vehicles in multibody system dynamics scenarios.

scholarly journals Modeling debris-flow runout patterns on two alpine fans with different dynamic simulation models

2015 ◽  
Vol 15 (7) ◽  
pp. 1483-1492 ◽  
Author(s):  
K. Schraml ◽  
B. Thomschitz ◽  
B. W. McArdell ◽  
C. Graf ◽  
R. Kaitna
Keyword(s):  
Numerical Simulation ◽  
Debris Flow ◽  
Mass Movement ◽  
Simulation Models ◽  
Realistic Model ◽  
Three Dimensions ◽  
Model Parameters ◽  
Alpine Regions ◽  
Digital Elevation ◽  
Higher Sensitivity

Abstract. Predicting potential deposition areas of future debris-flow events is important for engineering hazard assessment in alpine regions. To this end, numerical simulation models are commonly used tools. However, knowledge of appropriate model parameters is essential but often not available. In this study we use two numerical simulation models, RAMMS–DF (rapid mass movement system–debris-flow) and DAN3D (dynamic analysis of landslides in three dimensions), to back-calculate two well-documented debris-flow events in Austria and to compare the range and sensitivity of input parameters for the Voellmy flow model. All simulations are based on the same digital elevation models and similar boundary conditions. Our results show that observed deposition patterns are best matched with a parameter set of μ [–] and ξ [m s-2], ranging between 0.07 to 0.11 and 200 to 300 m s-2, respectively, for RAMMS–DF, and between 0.07 to 0.08 and 300 to 400 m s-2, respectively, for DAN3D. Sensitivity analysis shows a higher sensitivity of model parameters for the DAN3D model than for the RAMMS–DF model. This contributes to the evaluation of realistic model parameters for simulation of debris-flows in steep mountain catchments and highlights the sensitivity of the models.

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