scholarly journals Study on Hydraulic Incipient Motion Model of Reinforced Tailings

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2033
Author(s):  
Kehui Liu ◽  
Hai Cai ◽  
Xiaofei Jing ◽  
Yulong Chen ◽  
Lu Li ◽  
...  
Keyword(s):  
Tailings Dam ◽  
Motion Model ◽  
Test Results ◽  
Incipient Motion ◽  
Motion Direction ◽  
Incipient Velocity ◽  
Theoretical Support ◽  
Tailings Dams ◽  
Start Up ◽  
Property Losses

Once the flood overtopping accident of a reinforced tailings dam occurs, it will cause great property losses and serious environmental pollution to the downstream residents. In order to further study the microscopic characteristics of the hydraulic erosion of reinforced tailings dams, considering that the beginning of reinforced tailings particles is the basis of flooding and erosion of reinforced tailings dams, in this paper, a reinforced tailings hydraulic erosion facility was used to carry out the tailings particle start-up test with reinforcement spacing of 5.0, 2.5, 1.7, 1.3, and 1.0 cm, and the influence the law of critical incipient velocity of tailings particles with different reinforcement spacing was revealed. The test results show that, the smaller the reinforcement spacing, the larger the incipient velocity of the reinforced tailings sample. Based on the sediment incipient motion theory, it is assumed that the resistance direction of particle incipient motion is opposite to the particle motion direction. A reinforcement coefficient is introduced to establish the incipient velocity formula of reinforced tailings particles. This model can provide theoretical support for the study of the hydraulic erosion rate of a reinforced tailings dam.

scholarly journals Hydraulic Erosion Rate of Reinforced Tailings: Laboratory Investigation and Prediction Model

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Xuanyi Chen ◽  
Xiaofei Jing ◽  
Hai Cai ◽  
Yijun Wang ◽  
Luhua Ye
Keyword(s):  
Potential Energy ◽  
Prediction Model ◽  
Laboratory Investigation ◽  
Erosion Rate ◽  
Failure Modes ◽  
The Self ◽  
Tailings Dam ◽  
Test Results ◽  
Tailings Dams ◽  
Overtopping Failure

Tailings dams are high-potential-energy dams built to store various ore tailings, and the overtopping failure caused by hydraulic erosion is one of the most common failure modes. The characteristics of hydraulic erosion of the reinforced tailings were studied by using the self-made erosion apparatus with four kinds of reinforcement spacing 2.5, 1.7, 1.3, and 1.0 cm, respectively. The test results show a positive correlation between the reinforcement spacing and erosion rate of tailings. Based on the sediment scouring theory, the scouring constant in the erosion rate formula is determined to be 0.056 mm/s; a prediction model for the hydraulic erosion rate of reinforced tailings is established by introducing the collapse coefficient into the results of the overflow test of reinforced tailings. This model can provide a reference for the prediction of overtopping-induced erosion failure of the reinforced tailings dam.

scholarly journals Effects of Geosynthetic Reinforcement on Tailings Accumulation Dams

Water ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 2986
Author(s):  
Changbo Du ◽  
Lidong Liang ◽  
Fu Yi ◽  
Ben Niu
Keyword(s):  
Comparative Analysis ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Earth Pressure ◽  
Good Choice ◽  
Tailings Dam ◽  
Test Results ◽  
Reinforcement Effect ◽  
Tailings Dams ◽  
Over Time

Owing to the complexity of current reinforcement mechanisms, test results from existing models alone cannot provide a basis for the design of new tailings dam reinforcement projects. On-site reinforced tailings accumulation dam testing is thus required to further understand the reinforcement mechanism. In this study, the influence of reinforcement on tailings dams and the variation law of pore water pressure (PWP) and internal pressure (IP) in the dam body after slurry discharge were analysed, and a comparative analysis was performed. The results showed that during the field test, the PWP and internal earth pressure of the accumulation dam after grouting gradually increased over time. Reinforcement can greatly reduce the PWP and IP of the reinforced dam; compared with geotextiles, the reinforcement effect of geogrids is slightly greater. Based on these results, we conclude that geosynthetics are a good choice for strengthening tailings accumulation dams.

scholarly journals Experimental Study on Permeability Coefficient in Layered Fine Tailings under Seepage Condition

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Tao Dong ◽  
Ping Cao ◽  
Rong Gui ◽  
Qibin Lin ◽  
Zhizhen Liu
Keyword(s):  
Permeability Coefficient ◽  
Average Particle Size ◽  
Average Particle ◽  
Tailings Dam ◽  
Test Results ◽  
Initial State ◽  
Fine Grained ◽  
Tailings Dams ◽  
Fine Tailings ◽  
Seepage Characteristics

Nearly half of the tailings dams in China are in a state of high-security risks and overservice, and the safety of these tailings dams has always been a concern for relevant scholars. The seepage characteristics of tailings are one of the essential factors affecting the safety of tailings dam. Now, due to the improvement of mineral processing technology, there are many fine tailings dam; the study of the seepage characteristics of the tailings dam is no longer applicable. Fine-grained tailings form uneven deposition in these tailings dams, resulting in the permeability of tailings not conforming to the previous law. Therefore, it is of great significance to study the permeability of fine-grained tailings with uneven deposition. In this paper, the physical model of the simulated tailings dam is established to study the influence of the dry beach slope on the distribution and deposition law of fine tailings during discharge. The test results show that the average particle size of tailings decreases along the length of dry beach, showing the phenomenon of coarsening upstream and thinning downstream. Then, based on the data of fine tailings deposition, the variation characteristics of the permeability coefficient of layered tailings under stable and unstable seepage conditions are studied. The test results show that the variation process of tailings permeability coefficient can be divided into four stages: rapid compaction stage, slow compaction stage, failure stage, and stable stage. Under stable and unstable seepage conditions, the permeability coefficients of unstratified tailing sand are about 10% and 15% higher, respectively, than those in the initial state. The permeability coefficient of layered tailings formed by uneven settlement changes more obviously, which is about 12% and 20% higher than the initial state.

Numerical Analysis of Safety on Waste-Dumping Cover-Slope out of the Tailings Dam

2014 ◽  
Vol 501-504 ◽  
pp. 178-184
Author(s):  
Kai Yang ◽  
Shu Ran Lv ◽  
Chun Xue Wang
Keyword(s):  
Production Cost ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Bottom Layer ◽  
Tailings Dam ◽  
Waste Dump ◽  
Mining Companies ◽  
Tailings Dams ◽  
Before And After ◽  
Dump Slope

Mining companies intend to solve the problem of waste dump and reduce the production cost by dumping a large number of waste soils to cover slope outside the running tailings. Therefore, in order to discuss the safety of waste dump slope covering in front of the tailings dam, numerical method was adopted to study the seepage-line change law, the pore water pressure and anti-sliding safety before and after the waste dump covering out of tailings dam. The researches show that the key to waste-dump slope safety are the drainage performance of waste dump bottom layer and the anti-sliding safety of waste dump soil. The appropriate waste dump slope work can improves the tailings dams safety and solves the waste dump problem in mining production.

scholarly journals Measures for Resource Saving for Diesel Locomotives

2018 ◽  
Vol 7 (4.3) ◽  
pp. 152 ◽  
Author(s):  
Dmytro Aulin ◽  
Artem Zinkivskyi ◽  
Oleksandr Anatskyi ◽  
Dmytro Kovalenko
Keyword(s):  
Diesel Engine ◽  
Initial Moment ◽  
Test Results ◽  
Economic Costs ◽  
Resource Saving ◽  
Start Up ◽  
Railway Industry ◽  
Wear And Tear ◽  
Cylinder Piston ◽  
Engine Components

This article discusses the measures for efficient use of fuel and energy resources in the railway industry. The calculation of the initial moment of starting the diesel engine and the necessary position of its crankshaft is made, on the basis of which it is proposed to modernize the locomotive start-up system with a decompressor. These measures are aimed at reducing the dynamic loads of engine components and reducing their wear and tear, as well as failure preventing. A method for the clean-up of fuel systems and the cylinder-piston diesel engine group of diesel locomotives was developed and tested using a special cleaning liquid that dissolves and removes solidified particles from pipelines and tanks. Measures have been proposed on the use of advanced models to test the modernized locomotives that will reduce the duration of the tests, resource and economic costs. The use of advanced testing model involves choosing the level of accuracy of the test results and, consequently, their duration and cost.  

scholarly journals Lyapunov Based Estimation of Flight Stability Boundary under Icing Conditions

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Binbin Pei ◽  
Haojun Xu ◽  
Yuan Xue
Keyword(s):  
Equilibrium Point ◽  
External Disturbance ◽  
Stability Boundary ◽  
Wind Tunnel Test ◽  
Test Results ◽  
Theoretical Support ◽  
Effect Model ◽  
Short Period ◽  
The Stability ◽  
Period Model

Current fight boundary of the envelope protection in icing conditions is usually defined by the critical values of state parameters; however, such method does not take the interrelationship of each parameter and the effect of the external disturbance into consideration. This paper proposes constructing the stability boundary of the aircraft in icing conditions through analyzing the region of attraction (ROA) around the equilibrium point. Nonlinear icing effect model is proposed according to existing wind tunnel test results. On this basis, the iced polynomial short period model can be deduced further to obtain the stability boundary under icing conditions using ROA analysis. Simulation results for a series of icing severity demonstrate that, regardless of the icing severity, the boundary of the calculated ROA can be treated as an estimation of the stability boundary around an equilibrium point. The proposed methodology is believed to be a promising way for ROA analysis and stability boundary construction of the aircraft in icing conditions, and it will provide theoretical support for multiple boundary protection of icing tolerant flight.

scholarly journals Use of Basalt Fiber-Reinforced Tailings for Improving the Stability of Tailings Dam

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1306 ◽  
Author(s):  
Binbin Zheng ◽  
Dongming Zhang ◽  
Weisha Liu ◽  
Yonghao Yang ◽  
Han Yang
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Fiber Length ◽  
Basalt Fiber ◽  
Confining Pressure ◽  
Dry Density ◽  
Tailings Dam ◽  
Fiber Reinforced ◽  
Tailings Dams ◽  
The Stability

As one of the largest artificial geotechnical structures on earth, the tailings dams are classified as one of the high-risk sources in China’s industry. How to improve the stability and safety of tailings dams remains a challenge for mine operators currently. In this paper, an innovative method is presented for improving the stability of tailings dams, in which the basalt fiber is used to reinforce tailings. The mechanical properties of tailings used for dam-construction have a great influence on the stability of tailings dam. In order to investigate the mechanical performance of basalt fiber-reinforced tailings (BFRT), a series of laboratory triaxial tests were conducted. The effects of five parameters (fiber length, fiber content, particle size, dry density and confining pressure) on the mechanical properties of BFRT were studied. The microstructure and the behavior of interfaces between basalt fibers and tailings particles were analyzed by using scanning electron microscopy (SEM). The triaxial experimental test results show that the mechanical properties of BFRT increase with the increases of fiber length and content, particle size, dry density and confining pressure. The SEM results indicate that the interfacial interaction between fibers and tailings particles is mainly affected by particle shape.

The Slope Risk Analysis of Tailings Dam under the Coupling Effect of Rainstorms and Earthquakes

2012 ◽  
Vol 170-173 ◽  
pp. 1911-1914
Author(s):  
Kun Yang ◽  
Zhi Chao Ma
Keyword(s):  
Risk Analysis ◽  
Coupling Effect ◽  
Seismic Intensity ◽  
Reliability Theory ◽  
Tailings Dam ◽  
Mechanical Parameters ◽  
Material Parameters ◽  
Tailings Dams ◽  
Natural Factors ◽  
Heavy Rains

For slope risk analysis of tailings dam, the current research focuses on treating physical and mechanical parameters of tailing materials as the basic random variables. The influence of the external natural random factors is considered little. In practice, the slope stability of tailings dam is influenced by not only their random material parameters but the various natural factors including the changes of water level and the seismic intensity size. As a rule of thumb, there might be heavy rains before the earthquake. Therefore, it is necessary to comprehensively consider the slope risk of tailings dam under the coupling effect of rainstorms and earthquakes. Aiming at this problem, reliability theory was employed in this paper to study the influence under both rainstorms and earthquake actions. In this project, the slope risk analysis of tailings dams is evaluated under natural multi-random factors.

Properties of the power conditioning system with a five-level cascaded converter and supercapacitor energy storage

2011 ◽  
Vol 59 (4) ◽  
pp. 525-534
Author(s):  
M. Zygmanowski ◽  
B. Grzesik ◽  
J. Michalak
Keyword(s):  
Energy Storage ◽  
Laboratory Model ◽  
Test Results ◽  
Power Losses ◽  
Power Conditioning ◽  
Voltage Balancing ◽  
Start Up ◽  
Cascaded Converter ◽  
Supercapacitor Energy Storage ◽  
Power Electronic Converter

Properties of the power conditioning system with a five-level cascaded converter and supercapacitor energy storage The paper presents the power conditioning system (PCS) with a five-level cascaded H-bridge converter and supercapacitor energy storage. The paper focuses on such properties of a power electronic converter as its operation, power losses, start-up as well as the DC-link voltage balancing method and controller. A laboratory model of the PCS and its test results have been presented.

scholarly journals Analisis Perbandingan Algoritma Decision Tree, kNN, dan Naive Bayes untuk Prediksi Kesuksesan Start-up

2021 ◽  
Vol 6 (3) ◽  
pp. 178-188
Author(s):  
Adhitya Prayoga Permana ◽  
Kurniyatul Ainiyah ◽  
Khadijah Fahmi Hayati Holle
Keyword(s):  
Decision Tree ◽  
Naive Bayes ◽  
Naïve Bayes ◽  
Test Results ◽  
Decision Tree Algorithm ◽  
Tree Algorithm ◽  
Start Up ◽  
The Many ◽  
Start Ups

Start-ups have a very important role in economic growth, the existence of a start-up can open up many new jobs. However, not all start-ups that are developing can become successful start-ups. This is because start-ups have a high failure rate, data shows that 75% of start-ups fail in their development. Therefore, it is important to classify the successful and failed start-ups, so that later it can be used to see the factors that most influence start-up success, and can also predict the success of a start-up. Among the many classifications in data mining, the Decision Tree, kNN, and Naïve Bayes algorithms are the algorithms that the authors chose to classify the 923 start-up data records that were previously obtained. The test results using cross-validation and T-test show that the Decision Tree Algorithm is the most appropriate algorithm for classifying in this case study. This is evidenced by the accuracy value obtained from the Decision Tree algorithm, which is greater than other algorithms, which is 79.29%, while the kNN algorithm has an accuracy value of 66.69%, and Naive Bayes is 64.21%.

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