scholarly journals Methodology for Automated Monitoring of Induced Vibrations in Tailings Dams Built Upstream

2021 ◽  
Author(s):  
Gustavo Marçal De Sousa ◽  
Sérgio Augusto Ferreira ◽  
Romero César Gomes
Keyword(s):  
Vibration Monitoring ◽  
Surrounding Area ◽  
Safety Control ◽  
Industrial Plants ◽  
Analysis Techniques ◽  
Automated Monitoring ◽  
Tailings Dams ◽  
Advanced Analysis ◽  
Dam Stability ◽  
The Stability

Abstract Induced vibrations in tailings dams in Brazil became subject to studies after two major accidents in upstream-built structures. These ground vibrations may be responsible for liquefaction triggers and that motivated the development of this paper, which consists in the presentation of a methodology to perform homogeneous vibration monitoring tests along the entire embankment with an initial offline stage that later progressed to an automated process that represents the core object of the paper. Data collected from the initial monitoring enabled analyses of dam stability when correlating vibration levels in the embankment. As a consequence of such analyses, it was possible to parameterize control levels associated to safety criteria. Monitoring methodology, analysis techniques and gains resulting from the use of automated monitoring systems are presented herein. Parameterized control levels regarding the structure under study as well as their association to the stability condition, analysis of liquefaction trigger set for vibration values, advanced analysis of seismographic records and an automated operational vibration control system from monitoring using seismographic stations are shown. The implementation of the automated monitoring system associated to safety control levels allowed a robust diagnosis of eventual structural damages caused by vibrations in dams. That methodology was applied to a dam in operation and permitted evaluation of operation continuity concerning industrial plants and different operations with earthworks equipment on the embankment and its surrounding area.

Numerical Analysis of the Impact of the Stope Blasting Vibration on Tailings Dam Stability Based on GeoStudio

2014 ◽  
Vol 501-504 ◽  
pp. 200-206
Author(s):  
Qing Nan Wei ◽  
Shu Ran Lv
Keyword(s):  
Vibration Monitoring ◽  
Vibration Velocity ◽  
Blasting Vibration ◽  
Tailings Dam ◽  
Vibration Acceleration ◽  
Tailings Dams ◽  
Stability Against Sliding ◽  
Dam Stability ◽  
The Stability ◽  
The Impact

In this paper, based on the establishment of the finite element calculating model, the influence of the blasting vibration to tailings dams stability was analyzed in accordance with actual stope blasting vibration monitoring data. The laws of the blasting vibrations impact on tailings dam stability was reached by importing different vibration amplitude of vibration wave intensity. When the blasting vibration acceleration remained under 0.333g and vibration velocity remained under 17.005cm/s, the coefficient of the healthy tailings dam stability against sliding has a increasing trend with the increase of vibration strength. When the vibration acceleration and the vibration velocity reached the maximum value, the coefficient rapidly decline; But the influence of stope blasting vibration on the stability of the risky tailings dams is more significant. The coefficient of stability against sliding had a straight-line decrease to the risky tailings dams. In Engineering, more than 4 times margin is considered to find the control vibration velocity. The value is 4.25 cm/s. An analysis shows that the effect of blasting vibration on healthy tailings dam stability has two sides. When the blasting vibration intensity remains within control vibration velocity, it can be beneficial to the stability of tailings dam. Otherwise it will be harmful.

Study on Reliability Analysis of Tailings Dam Stability

2007 ◽  
Vol 353-358 ◽  
pp. 2619-2622
Author(s):  
Chao Zhang ◽  
Chun He Yang ◽  
Feng Chen
Keyword(s):  
Probability Distribution ◽  
Reliability Analysis ◽  
Limit Equilibrium ◽  
Reliability Theory ◽  
Sensitivity Analyses ◽  
Tailings Dam ◽  
Tailings Dams ◽  
Dam Stability ◽  
The Stability ◽  
Distribution Type

Since the construction method of tailings dams determines the uneven distribution of tailings, a reliability theory is introduced to analyze the stability of tailings dams. Based on the limit equilibrium method and reliability theory, the sensitivity and reliability of a typical tailings dam are analyzed. Reliability analyses with different types of the variable probability distribution types show that the effect of the probability distribution type on reliability analysis can almost be ignored. Besides, the sensitivity analyses of different variables show that the strength indexes and density of tailings will affect the analysis results of stability reliability. Therefore the strength indexes c, φ and density ρ must be considered as basic variables to analyze the stability reliability of tailings dams.

scholarly journals The Stability of Tailings Dams under Dry-Wet Cycles: A Case Study in Luonan, China

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1048 ◽  
Author(s):  
Xingang Wang ◽  
Hongbin Zhan ◽  
Jiading Wang ◽  
Ping Li
Keyword(s):  
Chemical Properties ◽  
Tailings Dam ◽  
Maximum Displacement ◽  
Finite Element Program ◽  
Direct Shear Tests ◽  
Tailings Dams ◽  
Tailings Sand ◽  
Element Program ◽  
Dam Stability ◽  
The Stability

Instability of tailings dams may result in loss of life and property and serious environmental pollution. The position of the tailings dam’s phreatic line varies due to continuously changing factors such as rainfall infiltration and discharge of tailings recycling water. Consequently, tailings dams undergo dry-wet (DW) cycles, accompanied by the appearance of a hydro-fluctuation belt. With dynamic development of the physical and chemical properties of tailings sand in the hydro-fluctuation belt, the stability of tailings dams is uncertain. In this study, direct shear tests were performed on the tailings sand collected from a tailings dam in Luonan, through which the shear strength parameters of tailings sand with DW cycles were obtained. Then, a method that efficiently calculates the phreatic line of the tailings dam under DW cycles was proposed. In addition, based on laboratory tests and the proposed phreatic line calculation method, we used a finite element program to evaluate the stability of the tailings dam that experienced different DW cycles. The calculated results showed that: (i) the damage effects of DW cycles gradually weakens as the number of DW cycles increases. (ii) With the increasing of DW cycles, the maximum displacement of the tailings dam increases from 0.5 mm to 22 mm, and the area of maximum displacement expanded mainly at the toe of the tailings dam and at the front edge of the hydro-fluctuation belt. (iii) The tailings dam safety factor decreases continuously with increasing DW cycles. This study may provide a novel method for analyzing the stability of tailings dams under different DW cycles as well as an important reference for improving tailings dam stability.

scholarly journals Comparative analysis: to and ni as case particles in Japanese

2021 ◽  
Vol 5 (1) ◽  
pp. 104-114
Author(s):  
Ngurah Indra Pradhana ◽  
I Gede Oeinada
Keyword(s):  
Comparative Analysis ◽  
The Other ◽  
Sentence Structure ◽  
Japanese Case ◽  
Analysis Techniques ◽  
Other Hand ◽  
Case Particles ◽  
Distributional Method ◽  
Advanced Analysis ◽  
The Relationship

This study focuses on particles To and Ni as case particles that function to express the relationship between nouns and predicates in a sentence focusing on the comparative analysis of the two case particles. Based on Tsujimura's opinion, it can be said that in Japanese, case particles are part of a phrase. Case particle is related to the function of the words in the sentence. The method used to analyze the data is Agih method (distributional method). Advanced analysis techniques with substitution techniques were applied in this study. This technique is used to study a case particle in the Japanese sentence structure. This research produces several things that are expected to be helpful to readers. To and Ni case particles can replace each other for the context of sentences that have the following meanings: Pairs Meaning, Translative Meaning, Accusative Meaning, and Ablative Meaning. But on the other hand, To and Ni as case particles can not substitution each other. Especially sentences with the following meanings:  accusative meaning, commitative meaning, partner meaning, citation meaning, alatif meaning, purpose meaning, time markers meaning, diathesis on passive sentences, diathesis on causative sentences, dative meaning, and locative meaning.

scholarly journals Providing Income Tax Article 21 Tax Incentives during the Covid-19 Pandemic for the Stability of Economic Growth in Indonesia

2021 ◽  
Vol 04 (03) ◽  
Author(s):  
Tiolina Evi ◽  
Keyword(s):  
Economic Growth ◽  
Income Tax ◽  
Qualitative Method ◽  
Tax Incentives ◽  
Know How ◽  
Analysis Techniques ◽  
Incentive Policies ◽  
The Government ◽  
The Stability ◽  
The Impact

This study discusses the policy analysis of providing Article 21 Income Tax incentives for taxpayers affected by the corona virus (covid-19) outbreak in order to maintain the stability of economic growth. The aim is to determine the effectiveness and influence of the provision of incentive policies by the government on economic conditions in society, especially in meeting household consumption needs. The problem raised in this study is the impact caused by the Covid-19 pandemic on employees who have been laid off, which the government then resolves by providing PPh 21 incentives with the aim of helping workers. The research method used in this research is a qualitative method. The purpose of this research is descriptive. Data collection techniques that have been collected, were analysed using qualitative data analysis techniques. The result of this research is to know the impact of government incentives for workers who have met the qualifications of the incentive recipients and to know how the scheme is in fulfilling this PPh 21 incentive.

Advanced Analysis Techniques for NVH and Sound Quality Improvement

2016 ◽  
Author(s):  
Thomas Deighan ◽  
Graeme Maclean ◽  
Nozomu Kato ◽  
Kiyofumi Sato
Keyword(s):  
Quality Improvement ◽  
Sound Quality ◽  
Analysis Techniques ◽  
Advanced Analysis

scholarly journals Stabilization Mechanism and Safety Control Strategy of the Deep Roadway with Complex Stress

2020 ◽  
Vol 2020 ◽  
pp. 1-18 ◽  
Author(s):  
Yang Yu ◽  
Dingchao Chen ◽  
Xiangqian Zhao ◽  
Xiangyu Wang ◽  
Lianying Zhang ◽  
...  
Keyword(s):  
Plastic Zone ◽  
Control Strategies ◽  
Pressure Coefficient ◽  
Horizontal Stress ◽  
Complex Stress ◽  
Rock Stratum ◽  
Safety Control ◽  
Coal Resources ◽  
Stress Environment ◽  
The Stability

With the increase of mining intensity of coal resources, some coal mines in China have gradually entered the deep mining stage. The complexity of the stress environment of the deep rock stratum leads to the difficulty of coal mining. Among them, the control of the deep roadway is one of the bottlenecks restricting the safety mining of the deep coal resources in China. By means of statistical analysis, the factors affecting the stability of the deep roadway were summed up: roadway occurrence environment, driving disturbance, and support means. The mechanical model of the deep roadway was established with the theory of elastic-plastic mechanics, the distribution characteristics of the plastic zone of the roadway were revealed, and the influence laws of lateral pressure coefficient, vertical stress, and support strength on the stability of the roadway were analyzed. Through numerical simulation, the law of stress, displacement and the plastic zone distribution evolution of the deep roadway, the mechanism of horizontal stress, and the mechanism of bolt support on the roadway were studied. On this basis, the safety control strategies to ensure the stability of the deep roadway were put forward: improving the strength of the roof and floor, especially the bearing part of the top angle and the side angle, enhancing the stability of the two sides of the roadway and controlling the floor heave, and making the surrounding rock of the deep roadway release pressure moderately, so as to make the roadway easy to be maintained under the low stress environment. These meaningful references were provided for the exploitation of deep coal resources in China.

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.

Study on the Capacity Increasing and Dam Heighten of Plain Reservoirs

2013 ◽  
Vol 353-356 ◽  
pp. 2531-2536
Author(s):  
Xiu Guang Song ◽  
Zhi Dong Zhou ◽  
Hong Bo Zhang ◽  
Hong Ya Yue
Keyword(s):  
Numerical Simulation ◽  
Comparative Analysis ◽  
Site Investigation ◽  
Seepage Flow ◽  
Differential Settlement ◽  
Construction Technology ◽  
Dam Stability ◽  
The Stability ◽  
Design Construction

In order to solve the problem of differential settlement, seepage flow and stability between the new and old dam boundary in capacity increasing of the plain reservoirs, the comparative analysis on the stability of the dam slope with different methods on dealing with the new and old dam boundary was performed by numerical simulation with FLAC3D. The result shows that combining the new and old dam by using geogrid indicates superiority for reducing differential settlement, improving the dam stability and safety, etc. In the meantime, on the basis of actual site investigation and theoretical analysis, combined with the requirements of design, construction and management in capacity increasing of the plain reservoirs, the key construction technology was put forward and widely applied foreground, which can improve the quality of the construction, reduce engineering disease and provide references for capacity increasing engineering of in plain reservoirs.

Comparison Between Linear and Nonlinear Transient Analysis Techniques to Find the Stability of a Rigid Rotor

1999 ◽  
Vol 121 (1) ◽  
pp. 198-201 ◽  
Author(s):  
Ram Turaga ◽  
A. S. Sekhar ◽  
B. C. Majumdar
Keyword(s):  
Transient Analysis ◽  
Stability Limit ◽  
Journal Bearings ◽  
Quantitative Comparison ◽  
Rigid Rotor ◽  
Analysis Techniques ◽  
Analysis Technique ◽  
Nonlinear Transient ◽  
Nonlinear Transient Analysis ◽  
The Stability

The subsynchronous whirl stability limit of a rigid rotor supported on two symmetrical finite journal bearings has been studied using the linearised perturbation method and the nonlinear transient analysis technique. A quantitative comparison for journal bearings with different l/d ratios has been provided.

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