Seismic stability of coal tailings dams with spatially variable and liquefiable coal tailings using pore pressure plasticity models

Salam, Sajjad; Xiao, Ming; Khosravifar, Arash; Ziotopoulou, Katerina

doi:10.1016/j.compgeo.2021.104017

“…The behaviour of the foundation bedrock is assumed to be linear elastic, while all the other materials are characterized by the UBCHyst model [12]. PM4Silt is a plane strain-stress ratio-controlled, critical state-compatible, bounding surface plasticity model for clays and plastic silts and has recently been used to represent tailings (e.g., [13,14,15]). Calibration of this model is performed with single-element simulations for the range of loading paths important for the tailings.…”

Section: Numerical Modellingmentioning

confidence: 99%

Seismic Fragility Functions of a Tailings Dam Affected by Subduction Earthquakes

Bellido,

Aguilar

2024

World Congress on Civil, Structural, and Environmental Engineering

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The seismic response of tailings dams is highly dependent on the intensity measures (IMs) of the input ground motions. For this reason, several researchers have used seismic fragility functions to evaluate the seismic performance of geotechnical structures. Seismic stability analyses of tailings dams are further challenged by the uncertainty and variability of IMs for a given earthquake scenario and site conditions. This study presents the seismic performance of a tailings dam affected by subduction earthquakes by generating fragility functions and analysing the effectiveness of different IMs in predicting a damage measure (DM), such as horizontal displacements. Our analyses are based on finite-difference numerical simulations using advanced constitutive models. The selected ground motions are compatible with the Maximum Credible Earthquake (MCE), which is common in the practice in South America. The results show that the Arias intensity is the most efficient and optimal IM in predicting the horizontal crest displacements of the dam. Furthermore, the analytical fragility functions based on numerical results using peak ground acceleration (PGA), Arias intensity (AI), cumulative absolute velocity (CAV), and peak ground velocity (PGV) are presented. The fragility functions can be a useful tool to assess the probability of damage levels for designed tailings dams based on their design earthquake and acceptable risk. In addition, the obtained fragility functions could be used to define alert levels to be considered in the operation manual of the tailings storage facility (TSF).

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“…The behaviour of the foundation bedrock is assumed to be linear elastic, while all the other materials are characterized by the UBCHyst model [12]. PM4Silt is a plane strain-stress ratio-controlled, critical statecompatible, bounding surface plasticity model for clays and plastic silts and has recently been used to represent tailings (e.g., [13,14,15]). Calibration of this model is performed with single-element simulations for the range of loading paths important for the tailings.…”

Section: Numerical Modellingmentioning

confidence: 99%

Seismic Vulnerability of a Tailings Dam Affected by Subduction Earthquakes

Bellido,

Aguilar

2024

IJCI

0

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The seismic response of tailings dams is highly dependent on the intensity measures (IMs) of the input ground motions. For this reason, several researchers have used seismic fragility functions to evaluate the seismic performance of geotechnical structures. Seismic stability analyses of tailings dams are further challenged by the uncertainty and variability of IMs for a given earthquake scenario and site conditions. This study presents the seismic performance of a tailings dam affected by subduction earthquakes by generating fragility functions and analysing the effectiveness of different IMs in predicting a damage measure (DM), such as horizontal displacements. Our analyses are based on finite-difference numerical simulations using advanced constitutive models. The selected ground motions are compatible with the Maximum Credible Earthquake (MCE), which is common in the practice in South America. The results show that the Arias intensity is the most efficient and optimal IM in predicting the horizontal crest displacements of the dam. Furthermore, the analytical fragility functions based on numerical results using peak ground acceleration (PGA), Arias intensity (AI), cumulative absolute velocity (CAV), and peak ground velocity (PGV) are presented. The fragility functions can be a useful tool to assess the probability of damage levels for designed tailings dams based on their design earthquake and acceptable risk. In addition, the obtained fragility functions could be used to define alert levels to be considered in the operation manual of the tailings storage facility (TSF).

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“…For example, some studies have discussed constitutive models for the static behavior of tailings materials [27,28]. In terms of dynamic properties, studies have explored constitutive models and dynamic strength [29,30], focusing on seismic safety characteristics of tailings clay and analyzing the influence of clay content and plasticity index on dynamic strength and pore pressure [31,32]. Compared with natural soils, the nonuniformity of tailings materials is more pronounced, making research more complex.…”

Section: Introductionmentioning

confidence: 99%

Mechanical Characteristics of Tailings in Different Depositional Zones: A Case Study of Caijiagou Tailings Pond in Shaanxi, China

Zhang,

Hu,

Li

et al. 2024

Advances in Civil Engineering

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This study examines the widespread practice of upstream tailings dam construction in metallurgical mines in China, conducting comprehensive testing and research on tailings from various depositional zones of the Caijiagou tailings pond. Analysis of the test results from three types of tailings reveals a systematic relationship between the mechanical characteristics of tailings and their depositional zones: the farther from the dam, the finer the tailings particles, categorized as silty clay tailing, silt tailing, and sandy silt tailing. Consistent patterns were observed in the consolidated-drained shear strength and consolidated-undrained effective shear strength of these tailings. Among these, sandy silt tailing exhibited the highest strength, whereas silty clay tailing displayed the lowest. The dynamic stress–strain relationships of all three tailings types are described using the Hardin equivalent viscous-elastic model, where the initial dynamic shear modulus and the maximum dynamic shear stress in the model increased with effective confining pressure. The damping ratios exhibited a three-stage trend with increasing dynamic strain: gradual increase, rapid growth, and then gradual stabilization. Under various consolidated stress conditions, the ratio of the damping ratio to the maximum damping ratio versus the reduction in dynamic shear modulus showed a favorable linear relationship. Under vibration conditions, the dynamic shear stress corresponding to tailings failure increased with higher effective confining pressure and consolidated stress ratio. Finally, this study summarizes the parameters and indicators related to the saturated tailings of iron mines used in the research. Our work provides a foundation and reference for the design of tailings dams and the development and utilization of abandoned tailings ponds.

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Seismic stability of coal tailings dams with spatially variable and liquefiable coal tailings using pore pressure plasticity models

Cited by 14 publications

References 24 publications

Seismic Fragility Functions of a Tailings Dam Affected by Subduction Earthquakes

Seismic Fragility Functions of a Tailings Dam Affected by Subduction Earthquakes

Seismic Vulnerability of a Tailings Dam Affected by Subduction Earthquakes

Mechanical Characteristics of Tailings in Different Depositional Zones: A Case Study of Caijiagou Tailings Pond in Shaanxi, China

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