scholarly journals The Influence of the Instantaneous Collapse of Tailings Pond on Downstream Facilities

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Sha Wang ◽  
Guodong Mei ◽  
Xuyang Xie ◽  
Lijie Guo
Keyword(s):  
Maximum Velocity ◽  
Dam Break ◽  
Dam Failure ◽  
Engineering Practice ◽  
Tailings Pond ◽  
2D Simulation ◽  
Total Potential ◽  
Flooding Depth ◽  
Flooded Area ◽  
The Impact

To evaluate the evolutionary processes guiding the formation of the tailings-water mixtures produced by the instantaneous collapse of tailings ponds and the influence of these on downstream facilities, a 2D simulation model with reasonable boundary and working conditions derived from actual engineering practice was built in this study, and the relationship between dam-break elevation and impact on downstream facilities was also analyzed to determine the relevant mechanism of influence. Computational results indicated that lowering the dam-break elevation caused the maximum velocity and flooding depth, along with the flooded area at monitoring points, to gradually increase. The occurrence times of maximum velocity and flooding depth were also gradually moved forward as the breaking elevation was reduced; this effect is directly related to the increase in the total potential energy at the lower break elevations. Further simulations of sand-prevent dams with different heights located downstream from a tailings pond were carried out to identify methods for mitigating the impact of dam failure. The results revealed that increasing the height of the sand-prevent dam reduced the production of tailings mixtures. Based on the results, the construction of a sand-prevent dam with a crest elevation equal to that of the starter dam was recommended.

scholarly journals Three-dimensional numerical simulation of mud flow from a tailings dam failure across complex terrain

2019 ◽  
Author(s):  
Dayu Yu ◽  
Liyu Tang ◽  
Chongcheng Chen
Keyword(s):  
Stokes Equations ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Dam Break ◽  
Dam Failure ◽  
Tailings Dam ◽  
In Situ Investigation ◽  
Impact Area ◽  
The Impact ◽  
Mud Flow

Abstract. A tailings dam accident can cause serious ecological disaster and property loss. Simulation of a tailings dam accident in advance is useful for understanding the tailings flow characteristics and assessing the possible extension of the impact area. In this paper, a three-dimensional (3-D) computational fluid dynamics (CFD) approach was proposed for reasonably and quickly predicting the flow routing and impact area of mud flow from a dam failure across 3-D terrain. The Navier–Stokes equations and the Bingham-Papanastasiou rheology model were employed as the governing equations and the constitutive model, respectively, and solved numerically in the finite volume method (FVM) scheme. The volume of fluid (VOF) method was used to track the interface between the tailings and air. The accuracy of the CFD model and the chosen numerical algorithm were validated using an analytical solution of the channel flow problem and a laboratory experiment on the dam break problem reported in the literature. In each issue, the obtained results were very close to the analytical solutions or experimental values. The proposed approach was then applied to simulate two scenarios of tailings dam failures, one of which was the Feijão tailings dam that failed on 25 January 2019, and the simulated routing coincided well with the in situ investigation. Therefore, the proposed approach does well in simulating the flow phenomenon of tailings after a dam break, and the numerical results can be used for early warning of disasters and emergency response.

scholarly journals Modeling and Risk Analysis of Dam-Break Flooding in a Semi‐Arid Montane Watershed.

2021 ◽  
Author(s):  
Aissam Gaagai ◽  
Hani Amir Aouissi ◽  
Andrey E. Krauklis ◽  
Juris Burlakovs ◽  
Ali Athamena ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Maximum Flow ◽  
Dam Break ◽  
Formation Time ◽  
Dam Failure ◽  
Wave Flow ◽  
Flood Wave ◽  
Embankment Dam ◽  
Breach Parameters ◽  
The Impact

The risk related to embankment dam breaches needs to be evaluated in order to prepare emergency action plans. The physical and hydrodynamic parameters of the flood wave generated from dam-failure event correspond to various breach parameters such as width, slope and formation time. This study aimed to simulate dam-breach failure scenario of Yabous dam (NE Algeria) and analyze its influence on areas (urban and natural environments) downstream the dam. The simulation was completed using the sensitivity analysis method in order to assess the impact of breach parameters on the dam-break scenario. The propagation of flood wave associated to dam-break was simulated using the one-dimensional HEC-RAS hydraulic model. This study ap-plied a sensitivity analysis of three breach parameters (slope, width, and formation time) in five sites selected downstream the embankment dam. The simulation showed that the maximum flow of the flood wave recorded at the level of the breach was 8768 m3/s, which gradually attenuated along the river course to reach 1579.2m3/s at about 8.5km downstream the dam. This study estab-lished the map of flood-prone areas that illustrated zones threatened with the flooding wave trig-gered by the dam failure due to extreme rainfall events. The sensitivity analysis showed that flood wave flow, height and width revealed positive and similar changes for the increase in adjustments (±25% and ±50%) of breach width and slope in the 5 sites. However, flood wave parameters of breach formation time showed significant trends that changed in the opposite direction compared to breach slope and width.

scholarly journals Three-dimensional numerical simulation of mud flow from a tailing dam failure across complex terrain

2020 ◽  
Vol 20 (3) ◽  
pp. 727-741 ◽  
Author(s):  
Dayu Yu ◽  
Liyu Tang ◽  
Chongcheng Chen
Keyword(s):  
Stokes Equations ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Dam Break ◽  
Dam Failure ◽  
In Situ Investigation ◽  
Tailing Dam ◽  
Impact Area ◽  
The Impact ◽  
Mud Flow

Abstract. A tailing dam accident can cause serious ecological disaster and property loss. Simulation of a tailing dam accident in advance is useful for understanding the tailing flow characteristics and assessing the possible extension of the impact area. In this paper, a three-dimensional (3-D) computational fluid dynamics (CFD) approach was proposed for reasonably and quickly predicting the flow routing and impact area of mud flow from a dam failure across 3-D terrain. The Navier–Stokes equations and the Bingham–Papanastasiou rheology model were employed as the governing equations and the constitutive model, respectively, and solved numerically in the finite volume method (FVM) scheme. The volume-of-fluid (VOF) method was used to track the interface between the tailings and air. The accuracy of the CFD model and the chosen numerical algorithm were validated using an analytical solution of the channel flow problem and a laboratory experiment on the dam-break problem reported in the literature. In each issue, the obtained results were very close to the analytical solutions or experimental values. The proposed approach was then applied to simulate two scenarios of tailing dam failures, one of which was the Feijão tailing dam that failed on 25 January 2019, and the simulated routing coincided well with the in situ investigation. Therefore, the proposed approach does well in simulating the flow phenomenon of tailings after a dam break, and the numerical results can be used for early warning of disasters and emergency response.

scholarly journals Experimental and Numerical Investigation of 3D Dam-Break Wave Propagation in an Enclosed Domain with Dry and Wet Bottom

2021 ◽  
Vol 11 (12) ◽  
pp. 5638
Author(s):  
Selahattin Kocaman ◽  
Stefania Evangelista ◽  
Hasan Guzel ◽  
Kaan Dal ◽  
Ada Yilmaz ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Numerical Models ◽  
Three Dimensional ◽  
Dam Break ◽  
Dam Failure ◽  
Navier Stokes ◽  
Negative Wave ◽  
Through Flow ◽  
Instantaneous Removal ◽  
Surface Patterns

Dam-break flood waves represent a severe threat to people and properties located in downstream regions. Although dam failure has been among the main subjects investigated in academia, little effort has been made toward investigating wave propagation under the influence of tailwater depth. This work presents three-dimensional (3D) numerical simulations of laboratory experiments of dam-breaks with tailwater performed at the Laboratory of Hydraulics of Iskenderun Technical University, Turkey. The dam-break wave was generated by the instantaneous removal of a sluice gate positioned at the center of a transversal wall forming the reservoir. Specifically, in order to understand the influence of tailwater level on wave propagation, three tests were conducted under the conditions of dry and wet downstream bottom with two different tailwater depths, respectively. The present research analyzes the propagation of the positive and negative wave originated by the dam-break, as well as the wave reflection against the channel’s downstream closed boundary. Digital image processing was used to track water surface patterns, and ultrasonic sensors were positioned at five different locations along the channel in order to obtain water stage hydrographs. Laboratory measurements were compared against the numerical results obtained through FLOW-3D commercial software, solving the 3D Reynolds-Averaged Navier–Stokes (RANS) with the k-ε turbulence model for closure, and Shallow Water Equations (SWEs). The comparison achieved a reasonable agreement with both numerical models, although the RANS showed in general, as expected, a better performance.

Study on Impact Compaction of Aeolian Sand Subgrade and its Effect Evaluation

2011 ◽  
Vol 378-379 ◽  
pp. 370-373
Author(s):  
Yu Qing Yuan ◽  
Xuan Cang Wang ◽  
Hui Jun Shao
Keyword(s):  
Rayleigh Wave ◽  
Impact Force ◽  
Engineering Practice ◽  
Effect Evaluation ◽  
Aeolian Sand ◽  
Field Compaction ◽  
Vibratory Compaction ◽  
Strength And Stiffness ◽  
The Impact ◽  
Elastic Stage

In order to solve the problem of aeolian sand subgrade compaction, we studied the technology of impact compaction, applied it to the engineering practice and analyzed its effect with Rayleigh wave. The technology of impact compaction can combine the compaction of potential energy and kinetic energy and make it easier for the materials to reach their elastic stage. With the combined function of "knead-roll-impact", the impact compaction road roller can compact the soil body and offer 6～10 times impact force and 3～4 times the depth of influence more than the vibratory roller. The impact compaction methods of aeolian sand subgrade were put forward. The comparative field compaction tests between impact and vibratory compaction are carried through, which are detected by Rayleigh wave. The results show that the impact compaction can make the density of the aeolian sand subgrade 2～5% higher than the vibratory compaction, and reach the influence depth of 7 metres. To sum up, the impact compaction can clearly increases the strength and stiffness of aeolian sand subgrade with a dynamic elastic modulus of 202.63MPa.

scholarly journals Failure of Zoned Earth Dam (An analysis of earth dam break)

2019 ◽  
Vol 27 (1) ◽  
pp. 344-353
Author(s):  
Abdul-Hassan K. Al-Shukur ◽  
Ranya Badea’ Mahmoud
Keyword(s):  
Water Level ◽  
Factor Of Safety ◽  
Limit Equilibrium ◽  
Water Flux ◽  
Dam Break ◽  
The Body ◽  
Earth Dam ◽  
Dam Failure ◽  
Maximum Water Level ◽  
Maximum Water

One of the most common type of embankment dam failure is the dam-break due to overtopping. In this study, the finite elements method has been used to analyze seepage and limit equilibrium method to study stability of the body of an earthfill dam during the flood condition. For this purpose, the software Geostudio 2012 is used through its subprograms SEEP/W and SLOPE/W. Al-Adhaim dam in Iraq has been chosen to analysis the 5 days of flood. It was found that the water flux of seepage during the flood reaches about 8.772*10-5. m3/sec when the water level 146.5 m at 2nd day. Seepage through the embankment at maximum water level increased by 55.1 % from maximum water level. It was concluded that the factor of safety against sliding in downstream side decrease with increasing water level and vice versa. It was also concluded that the deposits are getting more critical stability during the conditions of flood when the factor of safety value reaches 1.219 at 2nd day.

scholarly journals Discrete approach to stochastic parametrization and dimension reduction in nonlinear dynamics

2015 ◽  
Vol 112 (32) ◽  
pp. 9804-9809 ◽  
Author(s):  
Alexandre J. Chorin ◽  
Fei Lu
Keyword(s):  
Statistical Physics ◽  
Moving Average ◽  
Nonlinear Differential Equations ◽  
Numerical Algorithms ◽  
Engineering Practice ◽  
Fully Discrete ◽  
Lorenz 96 ◽  
The Impact ◽  
Time Dependent Problems ◽  
Approximate Equations

Many physical systems are described by nonlinear differential equations that are too complicated to solve in full. A natural way to proceed is to divide the variables into those that are of direct interest and those that are not, formulate solvable approximate equations for the variables of greater interest, and use data and statistical methods to account for the impact of the other variables. In the present paper we consider time-dependent problems and introduce a fully discrete solution method, which simplifies both the analysis of the data and the numerical algorithms. The resulting time series are identified by a NARMAX (nonlinear autoregression moving average with exogenous input) representation familiar from engineering practice. The connections with the Mori–Zwanzig formalism of statistical physics are discussed, as well as an application to the Lorenz 96 system.

scholarly journals Study on the Optimal Groove Shape and Glue Material for Fiber Bragg Grating Measuring Bolts

Sensors ◽  
2018 ◽  
Vol 18 (6) ◽  
pp. 1799 ◽  
Author(s):  
Yiming Zhao ◽  
Nong Zhang ◽  
Guangyao Si ◽  
Xuehua Li
Keyword(s):  
Fiber Bragg Grating ◽  
Linear Regression Analysis ◽  
Tensile Load ◽  
Tensile Tests ◽  
Bragg Grating ◽  
Engineering Practice ◽  
Direct Tension ◽  
Groove Shape ◽  
Fbg Sensors ◽  
The Impact

Fiber Bragg grating (FBG) measuring bolts, as a useful tool to evaluate the behaviors of steel bolts in underground engineering, can be manufactured by gluing the FBG sensors inside the grooves, which are usually symmetrical cuts along the steel bolt rod. The selection of the cut shape and the glue types could perceivably affect the final supporting strength of the bolts. Unfortunately, the impact of cut shape and glue type on bolting strength is not yet clear. In this study, based on direct tension tests, full tensile load–displacement curves of rock bolts with different groove shapes were obtained and analyzed. The effects of groove shape on the bolt strength were discussed, and the stress redistribution in the cross-section of a rock bolt with different grooves was simulated using ANSYS. The results indicated that the trapezoidal groove is best for manufacturing the FBG bolt due to its low reduction of supporting strength. Four types of glues commonly used for the FBG sensors were assessed by conducting tensile tests on the mechanical testing and simulation system and the static and dynamic optical interrogators system. Using linear regression analysis, the relationship between the reflected wavelength of FBG sensors and tensile load was obtained. Practical recommendations for glue selection in engineering practice are also provided.

Effect of Water-to-Cement Ratio on Cracking Resistance of Concrete at Early Age in Restrained Ring Specimens

2021 ◽  
Author(s):  
Dejian Shen ◽  
Yang Jiao ◽  
Ci Liu ◽  
Jiacheng Kang ◽  
Xiaojian Tang
Keyword(s):  
Development Rate ◽  
Ring Test ◽  
Engineering Practice ◽  
Early Age ◽  
Cracking Resistance ◽  
Multiple Parameters ◽  
Concrete Mixtures ◽  
Water To Cement Ratio ◽  
Study Results ◽  
The Impact

Nowadays, low water-to-cement (w/c) ratio has been put into widespread use in engineering practice. However, low w/c ratio may give rise to high self-desiccation, which may lead to the decrease of early-age cracking resistance. Investigating the impact of w/c ratio on cracking resistance is utterly meaningful to understand the cracking mechanism of concrete better. However, the corresponding investigations remain lacking, especially when the ring test is utilized. Ring tests for three concrete mixtures with different w/c ratios were conducted to investigate the early-age cracking resistance of concrete from multiple parameters in the present study. Results showed that: (1) the development rate of shrinkage of concrete for Mixture W50 was slower than Mixture W33 and W40; (2) the value and development rate of residual stress of concrete decreased when the w/c ratio increased; (3) the relaxed stress for all mixtures developed rapidly at very early age, and reached the maximum quickly; (4) the cracking resistance of concrete increased as the w/c ratio increased at early age.

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