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.

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.

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.

scholarly journals Numerical Analyses of Earthquake Induced Liquefaction and Deformation Behaviour of an Upstream Tailings Dam

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Muhammad Auchar Zardari ◽  
Hans Mattsson ◽  
Sven Knutsson ◽  
Muhammad Shehzad Khalid ◽  
Maria V. S. Ask ◽  
...  
Keyword(s):  
Finite Element ◽  
Seismic Event ◽  
Deformation Behaviour ◽  
Ground Surface ◽  
Tailings Dam ◽  
Limited Extent ◽  
Northern Sweden ◽  
Finite Element Program ◽  
Dynamic Analyses ◽  
Element Program

Much of the seismic activity of northern Sweden consists of micro-earthquakes occurring near postglacial faults. However, larger magnitude earthquakes do occur in Sweden, and earthquake statistics indicate that a magnitude 5 event is likely to occur once every century. This paper presents dynamic analyses of the effects of larger earthquakes on an upstream tailings dam at the Aitik copper mine in northern Sweden. The analyses were performed to evaluate the potential for liquefaction and to assess stability of the dam under two specific earthquakes: a commonly occurring magnitude 3.6 event and a more extreme earthquake of magnitude 5.8. The dynamic analyses were carried out with the finite element program PLAXIS using a recently implemented constitutive model called UBCSAND. The results indicate that the magnitude 5.8 earthquake would likely induce liquefaction in a limited zone located below the ground surface near the embankment dikes. It is interpreted that stability of the dam may not be affected due to the limited extent of the liquefied zone. Both types of earthquakes are predicted to induce tolerable magnitudes of displacements. The results of the postseismic slope stability analysis, performed for a state after a seismic event, suggest that the dam is stable during both the earthquakes.

3D Numerical Modelling of the Wave-Induced Response Around the Circular Caisson Founded on the Seabed

2008 ◽  
Author(s):  
Andrew H. C. Chan ◽  
Jian-Hua Ou
Keyword(s):  
Three Dimensional ◽  
Dynamic Interaction ◽  
Induced Response ◽  
Marine Structures ◽  
Finite Element Program ◽  
3D Numerical Modelling ◽  
Element Program ◽  
Main Factors ◽  
The Stability ◽  
Wave Induced

Wave-induced liquefaction is one of the main factors influence the stability of marine structures. However, the investigation on this phenomenon is complicated as the dynamic interaction between soil, pore fluid and the structure is closely coupled. In order to obtain a better understanding of the wave-induced response around the circular caisson founded in the seabed, three dimensional numerical analyses have been performed using the 3D finite element program DYNE3WAC in order to investigate the wave-induced response around the circular caisson.

Stability and Response of Rotors Supported on Active Magnetic Bearings

1993 ◽  
Author(s):  
K. Ramesh ◽  
R. G. Kirk
Keyword(s):  
Finite Element ◽  
Stability Analysis ◽  
Transfer Matrix ◽  
Magnetic Bearings ◽  
Active Magnetic Bearings ◽  
Finite Element Program ◽  
Element Program ◽  
Matrix Codes ◽  
The Stability

Abstract A PC-based program has been developed which is capable of performing stability analysis and response calculations of rotor-bearing systems. The paper discusses the modeling of rotors supported on active magnetic bearings (AMB) and highlights the advantages in the modeling using the finite element method, over the transfer matrix method. An 8-stage centrifugal compressor supported on AMB was chosen for the case study. The results for the stability analysis, obtained using the finite element program was compared with those obtained by the well established transfer matrix codes. The results of unbalance response, including the effects of sensor non collocation are presented and this demonstrates how an AMB supported rotor can experience a synchronous instability for selected sensor locations and balance distributions.

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.

Stability Analysis of Unsaturated Soil Slopes under Rainfall Infiltration

2012 ◽  
Vol 594-597 ◽  
pp. 126-129 ◽  
Author(s):  
Rong Fang Zhou ◽  
Xue Wen Lei ◽  
Qing Shan Meng ◽  
Cong Lin
Keyword(s):  
Unsaturated Soil ◽  
Equivalent Plastic Strain ◽  
Material Model ◽  
Rainfall Infiltration ◽  
Finite Element Program ◽  
Soil Material ◽  
Element Program ◽  
Stability Of Slope ◽  
Transient Seepage ◽  
The Stability

The principle of effective stress based on unsaturated soil material model and the boundary conditions of rainfall infiltration on the slope are introduced. The numerical model is built according to the example, and then the ABAQUS finite element program, which is combined with fluid-solid coupling, is used to simulate the problem of transient seepage field caused by rainfall infiltration. With the powerful post processing functions ability of ABAQUS program, we can observe the variation law with the time of pore-pressure distribution and displacement field and equivalent plastic strain. Moreover, the effect on the stability of slope under rainfall infiltration is analyzed.

Numerical Analysis of Geo-Grid to Enhence Stability of Tailings Dam

2013 ◽  
Vol 868 ◽  
pp. 287-290
Author(s):  
Yong Li Zhang ◽  
Yao Zhang ◽  
Yu Lin Ma ◽  
Chang Su ◽  
Xiang Feng Liu
Keyword(s):  
Working Conditions ◽  
Ultimate Load ◽  
Failure Surface ◽  
Fracture Plane ◽  
Structure Stability ◽  
Tailings Dam ◽  
Tailing Dam ◽  
Tailing Dams ◽  
Dam Stability ◽  
The Stability

The stability of tailing dams has recently become a hot issue on the engineering, and geo-synthetics curing processing applications are widely used. The influence of the tailings dam stability of geo-textile grid by calculating and analyzing with numerical simulation is studied. It reveals the mechanical behavior and the inherent law of the dam under different physical properties and different conditions of geo-grid. The force of reinforcement and the change law of ultimate load under different working conditions are systematically simulated by FLAC, and then analyze the formation process of sensitivity and fracture plane that influenced the ultimate load. The result shows: The failure surface is not such concentrated after joining the geo-textile grid and the safety factor increases 60%. The stability of the dam structure of tailing dam is effectively improved. Research has provided the basis for the structure stability of tailings dam's designing.

Stability Behavior of a Natural Circulation Loop with End Heat Exchangers

2005 ◽  
Vol 127 (7) ◽  
pp. 749-759 ◽  
Author(s):  
N. M. Rao ◽  
B. Maiti ◽  
P. K. Das
Keyword(s):  
Heat Exchangers ◽  
Natural Circulation ◽  
Circulation Rate ◽  
Finite Element Program ◽  
Stability Behavior ◽  
Wide Range ◽  
Element Program ◽  
The Stability ◽  
The One ◽  
Two Parameters

The present investigation describes the stability behavior of NCL with end heat exchangers. The one-dimensional transient conservation equations of the loop fluid and the two fluid streams of cold end and hot end heat exchangers are solved simultaneously using the finite element program. For the stability analysis the loop response is found for an imposed finite perturbation to the loop circulation rate. Though the stability may depend on the number of parameters, variation of two nondimensional parameters, namely Ch* and GrL, is studied. Selecting the specific combinations of the above two parameters three different cases of stability, namely, stable, neutrally stable, and unstable, are demonstrated. The stability behavior is scanned over a wide range of Ch* and GrL values and the stability envelope is also constructed.

The Analysis of Double-Nonlinearity Stability of Concrete Filled Steel-Tube Arch Bridge

2013 ◽  
Vol 724-725 ◽  
pp. 1709-1713 ◽  
Author(s):  
Xing Han ◽  
Bing Zhu ◽  
Gui Man Liu ◽  
Jun Ping Wang ◽  
Bao Shan Xiang
Keyword(s):  
Finite Element ◽  
Nonlinear Analysis ◽  
Steel Tube ◽  
Eigenvalue Analysis ◽  
Finite Element Program ◽  
Arch Bridge ◽  
Concrete Filled Steel Tube ◽  
Element Program ◽  
Load Displacement ◽  
The Stability

Taking a concrete-filled steel tube arch bridge with a span of 80m for example, the paper studies the stability of this bridge by using the general finite element program. The analysis introduces the method to deal with the stability of these bridges by FEM, also demonstrates the result of the eigenvalue analysis and dual nonlinear analysis according to an example. In eigenvalue analysis, the influence of the brace and the X-brace to this arch bridge`s stability are compared under different load cases; in dual nonlinear analysis, the load-displacement curves of three different load cases of the rib failure are given. All of these are some valuable to the stability of the concrete-filled steel tube arch bridge.

Sign in / Sign up

Export Citation Format

Share Document