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The risk of tailings dam-break disaster is dependent on the type of slurry and its flow characteristics. The flow characteristics of slurry surging from tailings dams collapse are directly influenced by grain size, breach width, slurry concentration, and surface roughness of the gully. Among these parameters, slurry concentration plays the most cri...
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... Furthermore, reclaiming abandoned tailings impoundments brings certain economic benefits to mines and protects the ecological environment [28][29][30]. Tailings generally have high water content and high compressibility [31,32]. It is a significant potential threat to mine safety and production [33], which was proposed by Wei et al. ...
Significant interest has been focused on recovery rates, recovery options, and recovery utilization when tailings impoundments are re-mined. However, the stability of the tailings dams during the recovery process is also a severe issue. Based on engineering geological surveys and laboratory tests, the evolution of the Tongling tailings impoundment’s instability characteristics under different recovery heights and diverse working conditions was analyzed by numerical simulation. Firstly, with the help of 2D software, the position of the tailings dam infiltration line and the alteration of the dam safety factor during the stoping process were calculated. Secondly, 3Dmine (2017) software was used to create the 3D surface structure of the tailings impoundment, and then a 3D numerical analysis model was established by means of Midas GTS NX software. The numerical simulation of seepage and stress analyses were conducted based on the model. Consequently, the evolution of the stability characteristics of tailings dam under different operating conditions was calculated. The research demonstrates that the dry beach length of the tailings pond gradually reduces with a decrease in the extraction height, resulting in a lower infiltration line. Under flood conditions, the saturation line has partial overflow due to the poor seepage discharge capacity of the dam. The total displacement of the dam body is inversely proportional to the retrieval height. The more extreme the analyzed working conditions, the more the safety factor will be reduced. Additionally, the plastic variation area of the dam body will be more comprehensive, which will increase the risk of a dam collapse.
... However, with the increase in tailings stacking height, it is inevitable that the water level in the tailings pond will be in high water level operation state for a long time and seriously damage the stability of tailings dam (Martin-Moreno et al. 2018;Do et al. 2021). In case of instability disaster of tailings dam, it will cause catastrophic loss of life and property of downstream people (Buch et al. 2021;Chen et al. 2021). For example, a particularly serious dam break accident occurred in the tailings pond of Xinta mining area in Xiangfen County, Shanxi Province, China, with an accident discharge capacity of 268,000 m 3 , affecting the area about 500-m downstream, causing 277 deaths and a direct economic loss of 96.192 million yuan (Rico et al. 2008). ...
With the impact of global climate change, dry tailing stack earth–rock dam endures more pressure from short-term extreme rainfall, which is easy to induce dam failure and leads to environmental disasters. In order to further clarify the threat caused by short-term extreme rainfall, taking the actual dry tailings stockpiling as the engineering background, using the research methods of indoor similarity test and numerical simulation, at the same time introducing the technical means of 3D reconstruction based on multi-directional images. The dynamic and high-precision point cloud was obtained, the evolution process of deformation and damage was described in detail, the mechanism and characteristics of disaster occurrence were revealed, and a comprehensive management method was proposed. Research shows that the evolution process of dry tailings rock stack earth–rock dam is divided into four stages: natural state, surface erosion, rill development, and gully and collapse. The dam abutment and dam foot are high-risk areas. The displacement generated by the earth–rock dam gradually spreads from the dam foot to the dam abutment and finally covers the entire outer dam surface; the plastic strain area is always concentrated at the dam foot. The main disaster modes are scouring and erosion disasters, gully and local collapse disasters, and soil erosion disasters. Natural cracks and the structural characteristics of soil particle size also affected the evolution of deformation and failure, as well as the occurrence of disasters. This study has important practical significance for the prediction of geological hazards and the development of disaster prevention and mitigation in tailings dry storage yards.
... Liu et al. used the direct shear test to determine the shear strength index of expansive soil under dry-wet cycles and revealed the relationship between crack development and shear strength [18]. Other previous studies have analyzed cracks in expansive soil under dry-wet cycles using image processing, quantified the crack index, analyzed the failure mechanism of slope cracks, and described the evolution mechanism of slope cracks [19][20][21][22][23][24][25]. Many previous studies have established numerical simulation experiments that consider the influence of cracks on the rainfall infiltration of expansive soil [26][27][28]. ...
... The total height of the slope model was 0.8 m, and the layered compaction method was used to construct the slope model [29]. Compaction was carried out 10 times using a small compactor to a degree of compaction of 70%, and each layer of compacted soil was cut using a cutting ring [19]. The cutting ring and soil ...
... The total height of the slope model was 0.8 m, and the layered compaction method was used to construct the slope model [29]. Compaction was carried out 10 times using a small compactor to a degree of compaction of 70%, and each layer of compacted soil was cut using a cutting ring [19]. The cutting ring and soil were weighed to calculate the degree of compaction of each layer. ...
This study investigated the crack propagation law of expansive soil slopes under drying–wetting conditions and the influence of cracks on slopes by conducting a large-scale indoor slope test subjected to drying–wetting cycles. The change in soil moisture content at different depths during the drying–wetting cycles was monitored using a moisture content sensor, and the variation in crack depths in the expansive soil during the drying process was measured using a crack depth detector. The cracks on the slope’s surface were processed using a self-made binarization program, and the crack evolution mechanism of the expansive soil during the drying process was analyzed. The rainfall-induced change in moisture content in the fractured soil was used to obtain the influence of moisture content change on expansive soils, and to analyze the dry–wet cycle failure mode of surface soil. The surface cracks of the soil were quantified by binary processing, and the area of the cracks and the area ratio of cracked soil to intact soil were calculated. Finally, by using PFC simulation software with the slope cracks and quantitative analysis results as parameters, it was confirmed that the greater the number of drying–wetting cycles, the greater the number of cracks, and the greater the damage to the slope.
... In this study, the numerical simulations were realized by considering a tailings slurry having a solids content by mass of 70%, a density of 1826.6 kg/m 3 , and a dynamic viscosity of 0.43 Pa·s [92]. It is well-known that the viscosity and flow characteristics of a tailings slurry depend largely on the solids content, as shown by Chen et al. [65]. More work is necessary to analyze the influence of the solids content on the flow of the tailings slurry and the impact forces on the downstream catch dams. ...
Tailings storage facilities (TSFs) are known as a time-bomb. The numerous failures of TSFs and the heavy catastrophic consequences associated with each failure of TSFs indicate that preventing measures are necessary for existing TSFs. One of the preventing measures is to construct catch dams along the downstream near TSFs. The design of catch dams requires a good understanding of the dynamic interaction between the tailing slurry flow and the catch dams. There are, however, very few studies on this aspect. In this study, a numerical code, named LS-DYNA, that is based on a combination of smoothed particle hydrodynamics and a finite element method, was used. The numerical modeling shows that the tailings slurry flow can generally be divided into four stages. In terms of stability analysis, a catch dam should be built either very close to or very far from the TSF. When the catch dam with an upstream slope of a very small inclination angle is too close to the tailings pond, it can be necessary to build a very high catch dam or a secondary catch dam. As the impacting force can increase and decrease with the fluctuations back-and-forth of the tailing slurry flow, the ideal inclination angle of the upstream slope of the catch dam is between 30° and 37.5°, while the construction of a catch dam with a vertical upstream slope should be avoided. However, a catch dam with steeper upstream slopes seems to be more efficient in intercepting tailings flow and allowing the people downstream more time for evacuation. All these aspects need to be considered to optimize the design of catch dams.
... A tailing pond is formed by the accumulation of tailings discharged from metal and non-metal mines, which has a high potential risk of debris flow (Vick, 1990;Wei et al., 2013). Once a tailing pond is damaged, it will lead to vast environmental pollution along with casualties and property losses (Villavicencio et al., 2014;Martin-Crespo et al., 2015;Santamarina et al., 2019;Chen et al., 2021). According to relevant statistics, seismic liquefaction is the second significant factor responsible for the failure of a tailing pond (Rico et al., 2008). ...
The construction period of most tailing ponds generally lasts for more than 10 years or even decades. During this period, it may be affected by more than one earthquake and is often subjected to vibrations generated by mining activities. The tailings liquefied by earthquakes or vibrations may experience dynamic loads again. Due to the low permeability of tailings, the reconsolidation process of tailings after liquefaction is prolonged. Therefore, changes in the nature of the tailings caused by previous earthquakes will affect the performance of the tailing dam in the subsequent earthquakes. Dynamic triaxial tests and bending element tests were conducted on two kinds of tailings from a copper mine in Southwest China to study this process. The tailing specimens will undergo two consolidation processes and subsequent cyclic loads during the test. The influence of reconsolidation degree, confining pressure, and particle size on the dynamic characteristics and wave velocity of the tailings after liquefaction under cyclic loading was measured. The results show that the reconsolidation degree significantly affects the trend of the excess pore water pressure ratio changing with the increase in the cycle number of loads. The reconsolidation process after liquefaction of tailings will improve its liquefaction resistance. The relationship between the ratio of the cycle number of liquefaction after reconsolidation to the cycle number of first liquefaction and the reconsolidation degree is proposed. In the entire experimental process, the shear wave velocity of the tailings gradually decreases when applying the cyclic load and gradually increases during the consolidation process, including the first consolidation before cyclic loading and reconsolidation after liquefaction. The research results are of great significance to the safe disposal of tailings, especially those in earthquake-prone areas.
Significant interest has been focused on recovery rates, recovery options, and recovery utilization when tailings impoundments are re-mined. However, the stability of the tailings dams during the recovery process is also a severe issue. Based on engineering geological survey and laboratory tests, the Tongling tailings impoundment’s characteristics of instability evolution under different recovery heights and diverse working conditions were analyzed by numerical simulation. Firstly, with the help of 2D software, the position of the tailings dam infiltration line and the alteration of the dam safety factor during the stoping process were calculated. Secondly, 3Dmine software was used to create the 3D surface structure of the tailings impoundment, and then a 3D numerical analysis model was established by means of Midas GTS NX software. The numerical simulation of seepage and stress analyses were conducted based on the model. Consequently, the evolution of the stability characteristics of tailings dam under different operating conditions was calculated. The research demonstrates that the dry beach length of the tailings pond gradually reduces with the decrease of the extraction height, resulting in a lower infiltration line. Under flood conditions, the saturation line has partial overflow due to the poor seepage discharge capacity of the dam. The total displacement of the dam body is inversely proportional to the retrieval height. The more extreme the analyzed working conditions, the more the safety factor will be reduced. Additionally, the plastic variation area of the dam body will be more comprehensive, which will increase the risk of a dam collapse.
